Hermione enjoyed her years as a pupil at Hogwarts and took assignments, classes, and school rules very seriously. She was often described as brilliant, to the point of being said to be "the brightest witch of her age". Her favourite subject was initially Charms, and later Arithmancy. Given her keen mind, some students - such as Terry Boot - wondered why Hermione was Sorted into Gryffindor rather than Ravenclaw. She admitted that the Sorting Hat did consider putting her in Ravenclaw.
It is likely that the Sorting Hat ultimately put her in Gryffindor because Hermione chose to be in it, just like Harry chose to not be in Slytherin. On the train she states that, "Gryffindor... sounds by far the best." She proved her rightful place in Gryffindor with her steadfast bravery and loyalty to her friends, Hogwarts, and Dumbledore's Army.

In spite of always wanting to follow the school rules, after Hermione became friends with Harry and Ron, she would disobey the rules along with them in order to successfully complete their group affairs. For example, she went with Ron and Harry into the third floor corridor in their first year, which students were temporarily forbidden from entering, in order to save the Philosopher's Stone; she assisted in creating the Polyjuice Potion in their second year; and although Harry was the one who taught Dumbledore's Army in their fifth year, she was the one who came up with the idea.

Hermione was a couple of weeks away from turning twelve when she boarded the Hogwarts Express in 1991, where she met Harry Potter and Ron Weasley while helping Neville Longbottom find his pet toad, Trevor. Hermione demonstrated knowledge and talent with magic beyond most of those her age, despite having only recently discovered that she was a witch. She wished to be a Gryffindor or a Ravenclaw, and her wish was granted considering she did get Sorted into Gryffindor.

Hermione soon proved to be the best in all her classes, eager to please the professors and to help others learn, albeit in a bossy way that made it difficult for her to make friends. Although she was a know-it-all, Hermione did often help Neville Longbottom, who struggled in most classes other than Herbology.

Hermione strictly followed all school rules and tried to prevent other students from breaking rules and getting into trouble. On one night, she followed Harry and Ron as they were leaving Gryffindor Tower to duel Draco Malfoy. They were chased by Argus Filch, acting on a tipoff by Malfoy, into the third-floor corridor — forbidden to students — where they came face-to-face with Fluffy, a three-headed dog belonging to Hagrid. Later on, she argued that her spying was to their benefit when she pointed out the dog had been standing on a trapdoor, which neither Harry nor Ron had noticed.

The friendship between Harry, Ron and Hermione was solidified when, on Hallowe'en in 1991, the three were forced to confront a mountain troll, which had been secretly let into the school by Professor Quirinus Quirrell. Unaware that a troll was on the loose in the school, Hermione had spent that day crying in the girls' bathroom after overhearing Ron making unkind comments about her. The troll made its way into the bathroom she was in, and Harry and Ron came to her rescue, saving her. When Professors Minerva McGonagall, Severus Snape and Quirinus Quirrell arrived at the scene, Hermione covered for the boys, claiming she was fighting the troll because she had thought that she could manage, having read a great deal about them, and that Ron and Harry had merely come to help her escape. From then, the three students were best friends and spent large amounts of time together.


The incident with the troll was by no means her only adventure in that first year. During the first Quidditch match, Hermione set Professor Snape's robes on fire when she thought he was jinxing Harry's broom. In the spring of 1992, Hagrid, now a friend of Hermione's through Harry, managed to procure a dragon egg, the unlicensed possession of which was illegal. The three children secretly helped Hagrid care for the beast, which he'd named Norbert. When the dragon was discovered, she and Harry smuggled it out of the school to some friends of Ron's elder brother, Charlie Weasley, who worked as a dragon-tamer. On their way back to the dormitories they were caught by Argus Filch, who escorted them to Professor Minerva McGonagall. Along with Neville and Draco, they received detention and had 50 points deducted each from their respective houses.

After their run-in with Fluffy, Harry deduced that whatever Hagrid had retrieved from Gringotts was beneath the trapdoor. Hagrid let it slip that "... What's under that trapdoor is strictly between Dumbledore and Nicholas Flamel". After much research turned up nothing, Harry was given a Dumbledore Chocolate Frog Card by Neville, which mentions Dumbledore's work in Alchemy with Flamel. This led Hermione to look at a large book on Alchemy which she had borrowed from the library for "a bit of light reading". After consulting the book, she realised that Fluffy was guarding the Philosopher's Stone.

Fearing that Lord Voldemort would return if he stole the stone, and believing that Snape was acting as a double agent and attempting to steal it, Harry decided to steal it first. When he told Hermione that he could go on alone, she rebuffed him. After the trio passed Fluffy, it was Hermione who freed Ron from a patch of Devil's Snare he had dropped into by conjuring Bluebell Flames. She later got herself and Harry through a challenge involving a Potion Riddle in order to obtain the right potion between many of them. Hermione used her logic to figure out the riddle and let Harry go forward without her, as there was only enough potion for one person.

Later, at the Farewell Feast in the Great Hall, Hermione, Harry, Ron, and Neville were all awarded extra House Points for bravery and heroism, allowing Gryffindor to win the House Cup. Hermione earned hers by correctly solving Professor Snape’s potion riddle.

Before she started her second year, Hermione wrote several letters to Harry at Privet Drive, all of which were intercepted by Dobby, as the house-elf wanted Harry to believe that his friends had forgotten him in order to prevent his return to Hogwarts. She and her parents also accompanied Harry and the Weasley family to Diagon Alley to shop for school supplies.

It was during her second school year that Hermione first encountered the prejudice and hatred surrounding her blood status, when Draco Malfoy called her a "filthy little Mudblood" after she told him off for insulting the Gryffindor Quidditch team. Hermione had never heard the highly offensive term but looking around at everyone around her, it was an obvious fact. Fred and George Weasley lunged at him, and Ron even tried to hex him, but it backfired, as his wand had been damaged. To help Hermione feel better about the incident, Hagrid urged her not to think about it, pointing out that she was a talented witch, regardless of what bigoted people said about her Muggle-born status.

Harry and Ron were surprised, and Ron annoyed, by Hermione's obvious crush on Gilderoy Lockhart, who became that year's Defence Against the Dark Arts professor. She scored full marks on the first quiz in his class, which consisted entirely of questions pertaining to Lockhart's books, including a question regarding his favourite colour (lilac) that most of the class had answered incorrectly. In fact, she went as far as to doodle hearts on her DADA assignments, not knowing until later that he was, in reality, a self-obsessed fraud.

On Hallowe'en, 1992 Hermione attended Nearly Headless Nick's Deathday Party with Harry and Ron. Whilst heading back upstairs, she followed Harry in a detour, after he claimed to be hearing voices. They discovered the caretaker's cat, Mrs Norris, petrified and the walls vandalised. Hermione began spending all her free time in the Hogwarts Library after she saw the writing on the corridor walls, which had said that the Chamber of Secrets had been re-opened. Despite hoping to read about the legend, she could not, as all the books had been previously checked out.

Hermione shocked everyone when she actually interrupted Professor Binns during a History of Magic class, asking about the Chamber of Secrets. This was the only known time when a student had asked the boring professor a question, and the class was interested in what he had to say. Professor Binns had stated that Salazar Slytherin had hidden a chamber which consisted of a horrible monster. It had been unleashed before once by an "Heir of Slytherin", petrifying many Muggle-born and had also killed a Ravenclaw girl, named Myrtle Warren, who began haunting the girls' lavatory and became known as Moaning Myrtle. Slytherin, a pure-blood loyalist, was against Muggle-born children being allowed to attend Hogwarts, but he was outnumbered by the other founders and Muggle-borns like Hermione were permitted as students. Slytherin fled the school, but rumours spread that he had built a hidden chamber; it was said that the school had been searched many times, but no such chamber had been found.

When Harry proposed the theory that Draco Malfoy was the Heir of Slytherin, Hermione and Ron agreed. Hermione suggested that they brew Polyjuice Potion, and temporarily transform themselves into Slytherin students in an attempt to find out the truth. She went even further by daring to check Moste Potente Potions out of the library using a note from Professor Lockhart - who had no idea what the book was - in the desire to research the potion. The book was in the Restricted Section and therefore unavailable to younger students without permission from a teacher. She hoped that they would be able to obtain a viable confession from Malfoy, if he was unaware he was being interrogated. She brewed the potion in Moaning Myrtle's bathroom, as no one used it due to Myrtle herself being highly irritating. She also risked serious consequences when she stole potion ingredients from Professor Snape's personal cupboards that were needed for the difficult potion, which took a month to brew.

Unfortunately, Hermione was unable to join Harry and Ron in the ruse with Polyjuice Potion because the hair she obtained from Slytherin Millicent Bulstrode during their scuffle in the Duelling Club was actually the hair of Bulstrode's cat. Hermione grew fur and a tail, and remained in the Hospital Wing for weeks as she did not transform back when the normal duration of effectiveness - one hour - was up. Harry and Ron, however, were able to use the potion she brewed to transform into Gregory Goyle and Vincent Crabbe, respectively. They entered the Slytherin common room, and through conversation with Draco Malfoy, realised that he was not the Heir of Slytherin, and was not involved in the opening of the Chamber after all.

Months after her recovery from the Polyjuice complication, Hermione suffered another accident. Drawing the connection between Harry hearing voices in the walls and him being a Parselmouth, she came to the conclusion that the creature attacking students must be a Basilisk, and rushed to the library to conduct further research. On her way back from the library, she warned the first person she saw, Penelope Clearwater, and advised her to look around corners with a mirror before going anywhere. It saved both their lives, because they were both petrified when they spotted the basilisk's eyes through the mirror instead of dying immediately as they would have done if they'd looked straight into its eyes.

Though she was petrified for the rest of the school year, Hermione was still able to assist Harry and Ron, for she had torn out the page on basilisks and scribbled on it "pipes", referencing the manner in which the creature had moved around the school undetected. Harry and Ron found it clenched in her hand when they were finally allowed to visit her in the Hospital Wing. Using this note and other information they had gathered, Harry and Ron were able to successfully put an end to Lord Voldemort's plans to resurrect his body through his memory stored in an old school diary.

Hermione was later cured with a Mandrake Restorative Draught created by Professor Sprout. Upon arriving at the Great Hall, she was immediately greeted by Nearly Headless Nick. After hugging Harry she exchanged an awkward greeting with Ron. Hermione was disappointed to learn that, as a special treat for the school, Professor Dumbledore cancelled the students' end of year exams, but she was intensely proud that her friends had solved the mystery.[21] That summer, Hermione went on holiday to France with her parents.

Just before she began the 1993-1994 school year, while visiting Diagon Alley with Harry and the Weasley family, Hermione met and adopted a ginger part-Kneazle cat named Crookshanks from the Magical Menagerie. However, her new bond with her cat caused friction with Ron and his pet rat Scabbers, as Crookshanks was always trying to catch the rat. Also at the beginning of this school year, Hermione obtained a Time-Turner from Professor McGonagall so she could double up on classes, though this was kept secret from everyone, even Harry and Ron.

When Harry received a Firebolt for Christmas with no note, Hermione reported it to Professor McGonagall, thinking it was sent by Sirius Black, whom everyone believed to be a dangerous murderer who was after Harry. His broom was taken away to be inspected, which caused a temporary rift between the two friends. There was further social strain for Hermione when Ron accused Crookshanks of eating Scabbers, who had disappeared.

Hermione poured herself into defending Buckbeak, the hippogriff on trial before the Committee for the Disposal of Dangerous Creatures for attacking Draco Malfoy during a Care of Magical Creatures class. Once the trio reconciled, after Hagrid told Harry and Ron how disappointed he was when they selfishly put the Firebolt and Scabbers over their friendship with Hermione, they apologised. Their attempt to save Buckbeak failed, as Lucius Malfoy frightened the Committee into deciding that the creature would be executed. Hermione was extremely upset by this news and grew furious to the point of slapping Draco Malfoy when he dared to mock Hagrid for his tears and being upset over Buckbeak's fate.

That year, Hermione was among the students who found Remus Lupin to be the best Defence Against the Dark Arts teacher they have ever had. She cleverly deduced that Professor Lupin was a werewolf, based on his Boggart taking the form of a full moon, the timing of his unexplained absences from class, and Professor Snape changing a lesson he took over to the subject of werewolves even though it wasn't due on the syllabus for weeks. However, she didn't expose Lupin, presumably because she believed he was a good teacher and didn't agree with the prejudice many hold against werewolves.

Divination, on the other hand, turned out to be a subject Hermione had no respect for or interest in, and soon dropped the subject after Professor Sybill Trelawney told her that she didn't posses the Second Sight and because she believed that Divination was an imprecise term of magic.[15]

On the day of Buckbeak's execution, the trio ventured down to console Hagrid. While in his cabin, Hermione discovered Scabbers, Ron's lost rat. Hagrid urged them to leave and they witnessed from a distance what they believed to be Buckbeak's execution. Before they could return to their dormitory, Scabbers bit Ron and fled. While chasing after the rat, they were attacked by a black dog, which pulled Ron by the leg into a tunnel beneath the Whomping Willow, which then attacked them.

Afterward, Hermione and Harry hurried after them eventually arriving in the Shrieking Shack, where Sirius Black, whose Animagus form was the black dog, confronted them. They were soon joined by Professor Lupin who was acting strangely, and Hermione told Harry and Ron of her belief that he was a werewolf, which he then confirmed. It was revealed that Sirius had been framed for the betrayal of James and Lily Potter, and that the true traitor was Peter Pettigrew, who had been hiding from the world as Ron's pet rat. Hermione also cast Expelliarmus on Snape when he discovered them, knocking him out, at which she was horrified.



Once it had been decided that Pettigrew would be turned over to the authorities rather than murdered, the motley group left the Shrieking Shack. When the full moon appeared, chaos ensued as Lupin transformed into a werewolf as, due to the chaotic turn of events, he hadn't taken the Wolfsbane potion that Professor Snape produced for him monthly in order for him to retain his humanity. In the chaos, Pettigrew attacked Ron and escaped, and Sirius had to transform into his dog form in order to protect Harry, Ron, and Hermione from the werewolf. Lupin was eventually distracted by a howl from the Forbidden Forest. Hermione and Harry rushed to Sirius' aid when they heard him moaning, but hundreds of Dementors descended on them, come to recapture Sirius. Sirius quickly fainted, and Harry told Hermione to think of something happy and attempt to cast a patronus as he was trying to himself, but they were both unable to cast one. As Harry conjured an incorporeal Patronus, Hermione passed out, leaving Harry to fight the Dementors alone. Harry held them off for a while but was eventually overwhelmed. The Dementors were about to perform the Kiss on Harry, Hermione, and Sirius when a mysterious figure in the distance cast a very powerful Patronus Charm to repel the Dementors. Unable to see properly in the resulting blinding light, Harry thought he glimpsed his father just before he, too, lost consciousness.

Harry and Hermione awoke in the Hospital Wing after being rescued by Severus Snape, who conjured stretchers for Hermione, Harry and Sirius. After realising that Sirius' soul was to be destroyed by the Dementor's Kiss and receiving vague, though instructive and useful, instructions from Dumbledore, Hermione used her Time-Turner to return herself and Harry to a time earlier in the evening. It was a very difficult task and Harry had to be constantly reminded by Hermione to stay concealed as being seen could cause irreparable damage to their timelines. Hermione agreed with Harry that it was difficult to watch their problems again, but she strictly said that they could do nothing about it, as bad things happened to wizards who tried to meddle with their past and future lives.

The two did, however, successfully use the opportunity to rescue Sirius and also Buckbeak, as it was hinted by Dumbledore that more than one innocent life could be spared that night. Whilst waiting, she discussed their saviour with Harry, and when Harry realised that it was not his father he saw but himself having travelled back in time, she claimed that none but a powerful wizard could have conjured a Patronus to drive away that many Dementors. As evidenced by her assertion that time-travelling was extremely dangerous, Hermione took great personal risk to save Sirius and Buckbeak. At the end of the year Hermione returned her Time-Turner, claiming it caused too much trouble and that she would drop a few subjects instead, which was a very big surprise to everyone.

Before her fourth year at Hogwarts, Hermione spent much of the summer holidays at the Burrow with Harry and Ron, sharing a room with Ginny Weasley. With the other Weasleys (excluding Molly Weasley), they attended the 1994 Quidditch World Cup in August. After the game, the communal campsite was set upon by Death Eaters. Hermione, Harry, and Ron fled into the woods and witnessed the casting of Morsmordre. Initially caught up in the chaos surrounding the effort to catch the caster, she took exception to the accusations levelled against Harry, and the many wizards' treatment of the house-elf Winky who had also been at the scene.

Once at Hogwarts, it was revealed to the students that former Auror Alastor Moody (who was, in fact, a polyjuiced Barty Crouch Jr) was to be the new Defence Against the Dark Arts professor, Lupin having left at the end of the previous year due to Snape outing his werewolf status. Moody was a hands-on professor who believed in a practical approach when it came to defence. One of his earliest lessons was on the Unforgivable Curses. Hermione and her fellow classmates witnessed the curses effects on a spider.

Hermione began a crusade for the liberation of house-elves by beginning the Society for the Promotion of Elfish Welfare, or what she and the group called S.P.E.W, (or, as Ronald Weasley called it, "spew") having been appalled by Bartemius Crouch's abusive treatment of his house-elf Winky. This did not earn her any popularity, as most believed that house-elves enjoy their work; indeed, even the house-elves did not like her campaigning. Harry, Ron, and Neville only reluctantly joined S.P.E.W., mostly in order to prevent Hermione from nagging them about it. Hagrid as well as Fred and George Weasley refused to join on the grounds that it would upset the house-elves. Despite this, Fred did tell Hermione how to get into the Hogwarts kitchens. One morning she (along with Harry and Ron) visited the kitchens, where she spoke to Dobby and Winky. Dobby was pleased to see Harry and his friends and proceeded to tell them his struggles as a freed elf.

While the trio were within the kitchen it was revealed that Winky was so saddened by the lose of her previous job that she had taken to drinking Butterbeer, as a means to get drunk and numb her pain. Hermione considered Dobby to be a good example of a free elf and tried to comfort Winky about being sacked by Crouch. This did little good, however, as Winky soon became upset by Hermione's claims that house-elves deserved to have holidays and wages. Winky was not the only elf bothered by this, as the other elves stated that proper house-elves would never need such things and to want them is considered very shameful.

After the events surrounding Harry's name coming out of the Goblet of Fire, Hermione was the only student who believed Harry's innocence. In fact, she "accepted his story without question." Even Ron was suspicious that Harry had cheated in order to gain more glory, creating a rift between the two for some time. Hermione helped Harry prepare for the first task of the Triwizard Tournament by helping him learn useful spells. Some of the spells were Stupefy, Impedimenta, Accio, and the Four-Point Spell. She also tried to get Harry and Ron to talk to one another multiple times.

Hermione unknowingly attracted the interest of Durmstrang Triwizard Champion and Bulgarian International Seeker, Viktor Krum. He was attracted to her due to her intelligence, unconventional beauty, and the manner in which she declined to hound him for autographs, unlike other girls. Krum began following Hermione to the library and other places around Hogwarts, including the library. This was something that Hermione found very irritating, as she couldn't work when surrounded by giggling girls, who had taken it upon themselves to follow Krum throughout the castle and the school grounds. Krum even bizarrely asked Harry if it was all right for him to pursue Hermione. He eventually asked her to attend the Yule Ball with him, and she accepted, not telling anyone but Ginny Weasley that she was his date.

Thus, when the pair arrived, many were stunned and jealous. Hermione wore robes of a "floaty, periwinkle-blue material," and her hair in an "elegant knot at the back of her head." The attention to her appearance was unusual, and she received many positive remarks on it. Even Draco Malfoy and Pansy Parkinson had nothing negative to say. Hermione commented that she had used Sleekeazy's Hair Potion, but that it was too much work to use it every day. Upon seeing Hermione with Krum, Ron was overcome with jealousy. Hermione had hoped for Ron to ask her, but his invitation was insensitive and at the last minute due to him not being able to find anyone else. The two rowed about it in the common room after the ball, in which she revealed that he should have asked her properly and not "as a last resort", but Ron misunderstood the point. After that, the two were seemingly more polite to each other, although more distant for a time and Ron continued to show dislike and distrust towards Krum.

Hermione was chosen as a "kidnap victim" for Krum during the Tournament's Second Task, something that she subsequently endured teasing over. She was taken to the bottom of the Black Lake to await rescue from Krum, who donned a half-shark Transfiguration. Krum managed to rescue her and carried her to the surface, where he revealed to her later that he "never felt this way about any other girl" and asked her to visit him in Bulgaria over the summer. Krum was jealous of Hermione's relationship with Harry Potter, thinking that there was something romantic between them that went beyond just plain friendship. The jealousy was founded based on the lies in the Daily Prophet and Harry was quick to inform Krum of these lies.

Rita Skeeter, a journalist for the Daily Prophet and unregistered Animagus, was hiding in beetle form in Hermione's hair during this conversation. Hermione had previously reprimanded Skeeter for printing horrible lies about Harry and Rubeus Hagrid. This angered the journalist, who wrote a scathing article on "the devious Miss Granger", claiming that she was toying with both Harry and Krum's affections and that she had developed a taste for famous wizards. Skeeter even went so far to claim that Hermione was possibly brewing love potions. In the words of Ron, Skeeter was making Hermione out to be a "Scarlet Woman", a phrase which made Hermione laugh. She called Hermione "plain" in the article, inspite of previously reporting Hermione as Harry's "stunningly pretty... girlfriend" by likely twisting and sensationalising the words of Colin Creevey and thus using this as the basis for the article. Although Hermione found the lies ridiculous, some people believed them and started sending Hermione hate mail, including one filled with Bubotuber Pus, and even Molly Weasley treated her coldly until Harry corrected her. Hermione vowed to get revenge on Skeeter for her libel, and wondered how she was getting her information, as several things Skeeter knew had only been discussed in private conversations. This led her to come to the realisation that Skeeter was an illegal unregistered Animagus, who took the form of a beetle to secretly witness confidential exchanges.

The students were shocked when Harry returned at the end of the third and final task with Cedric Diggory's dead body. Hermione was relieved to see Harry when he was brought to the infirmary by Professor Dumbledore. She was upset with the Minister for Magic, Cornelius Fudge, when he refused to believe Harry and Dumbledore about the truth of Voldemort's return. During her time with Harry in the Hospital Wing, she noticed Skeeter on a windowsill, attempting to eavesdrop, and captured her in the process. Hermione did not go against Harry's story when she finally heard it, sticking by her best friend.

On the ride home on the Hogwarts Express, Hermione happily revealed to Harry and Ron that she uncovered Skeeter's status as an unregistered Animagus and had trapped her in a jar. She kept Skeeter from writing for a year by threatening to expose her to the authorities. She single-handed drove Skeeter into poverty, gaining revenge for the pain caused to Harry and her other friends. However, with the return of Lord Voldemort and the murder of Cedric Diggory at the end of the school year, there were much more serious challenges ahead for Hermione and her friends.

Following the death of Cedric Diggory, the Ministry of Magic refused to accept Harry and Dumbledore's claims that Lord Voldemort had returned, and the Daily Prophet labelled them either liars or nutters. However, Hermione and Ron believed Harry and defended him against the criticism of doubtful classmates. Though occasionally Harry vented his frustration at them, the two stuck by him. The trio also wanted to become members of the reconvened Order of the Phoenix but were not allowed to because they were under-age. Hermione helped exterminate 12 Grimmauld Place, which served as headquarters for the Order, and was immensely relieved when Harry was acquitted of the charge of having used underage magic in the presence of a muggle, after him and Dudley Dursley were attacked by a Dementor in Little Whinging.

Before returning to Hogwarts, she and Ron learned that they had been appointed prefects for Gryffindor house, to the secret consternation of Harry, who couldn't believe Ron had been chosen over him. She took her position very seriously. Once the school year began, Hermione resumed some of her activism on behalf of house-elves, though she was not as intense about S.P.E.W. as she had been the previous year. She learned how to knit socks and hats for the house-elves and hid them in Gryffindor Tower, disguising them with crumpled rubbish in an attempt to trick the house-elves into accidentally freeing themselves. The elves found this attempt insulting, and they stopped cleaning the Tower at all. Dobby was the only one who enjoyed the gifts, took everything Hermione had made, and cleaned the Tower by himself, a fact which Hermione didn't know. Hermione was challenged in more ways than one that year when she met Luna Lovegood, whose belief in many things without logical grounds baffled Hermione. However, the two became friends after accepting one another's differences.

Meanwhile, it was not long before Hermione realised that the Ministry of Magic had decided to interfere at Hogwarts. Dolores Umbridge, a cruel, falsely sweet Ministry employee with a personality like "poisoned honey", was appointed as the new professor of Defence Against the Dark Arts. She refused to teach students practical defence, focusing only on theory, despite their OWLs being later that year. With this being the case, Hermione decided that Hogwarts needed a competent teacher and, together with Harry and Ron, founded Dumbledore's Army, a secret organisation in which students would gather after classes and be taught practical defensive spells. She suggested that Harry be the teacher; though he originally thought the idea ridiculous, he consented to teach the class. The name was suggested by Ginny, who recalled the conversation they'd had about Fudge's greatest fear being that Dumbledore would form an army of students if the Ministry did not intervene at Hogwarts.

One of the many spells Hermione learned was the Patronus Charm; hers took the corporeal form of an otter. Hermione became one of the few people brave enough to call Voldemort by his actual name. However, Hermione made the mistake of arranging the first meeting to take place in the Hog's Head, as opposed to the Three Broomsticks, which Sirius, appearing in the Gryffindor Common Room fire, said would have made it a lot more harder for anyone to overhear. Willy Widdershins, who was in the Hog's Head, went to Umbridge, who instituted Educational Decree Number Twenty-Four to forbid any type of students groups from being formed under her watchful eye.

Halfway through the year at Hogwarts, Harry had a vision of Voldemort's snake, Nagini, biting Mr Weasley during his task for the Order of the Phoenix. Mr Weasley was carried into St Mungo's Hospital, where Mrs Weasley screamed at him for trying to stitch his wound instead of healing it with magic. Hermione was one of the few who visited him and stayed at Number Twelve, Grimmauld Place for a couple of weeks until Mr Weasley was nursed back to health. Hermione had managed to convince her parents by telling them that skiing wasn't really her thing and that people who were serious about their exams stayed at Hogwarts and studied.

The D.A. brought Harry into greater contact with Cho Chang. After a meeting, Harry kissed Cho, and when he returned to the Gryffindor Common Room Hermione immediately guessed, asking if Cho had cornered him after the meeting. When Harry told them that Cho has been crying, she explained to Harry and Ron that Cho was having a hard time since Cedric Diggory, who she used to go out with, was killed by Lord Voldemort. Hermione later gave Harry advice on Cho and girls in general. In an effort to combat the lies being told about Harry, Hermione arranged for an interview during a Hogsmeade visit with Rita Skeeter to be printed in The Quibbler telling his side of the story, blackmailing Skeeter into penning it in a sympathetic tone. Despite being banned - or maybe because it was banned - it became the magazine's best-selling issue of all time.

It was Hermione's brilliant spell-work that ensured the security of Dumbledore's Army. She created coins enchanted with the Protean Charm, an advanced spell, as a method of communication, and jinxed the club's attendance sheet to give any tattler a horrendous rash on the face, which would spell out "SNEAK" in painful boils. This is exactly what happened to Marietta Edgecombe, a reluctant member of the D.A., having been brought to the meetings by Cho. Shortly before Easter, Marietta finally caved under the pressure from her ministry mother who worked in the the Floo Network Office and betrayed the D.A. to Umbridge. When Harry learned that they could not find a counter-curse to heal her face, he swelled with pride at Hermione's jinxing ability.

Dobby the house-elf learned of this turn of events and rushed to the Room of Requirement to warn Harry and the D.A. They immediately scattered, and most members escaped, but Harry was caught by Umbridge and several Slytherin students who were members of the Inquisitorial Squad. A search of the room uncovered the parchment that each member of the D.A. had signed, headed Dumbledore's Army. Finally having "proof" that Dumbledore was building an army to challenge the Ministry, Umbridge immediately contacted Cornelius Fudge. Dumbledore fled the school and Umbridge became Headmistress. Hermione was not exposed at that time, but later she was brought to Umbridge's office by the some members of the Inquisitorial Squad.

Late in the fall of that year, Hagrid, who had been missing for the entirety of the school year, returned to Hogwarts. Hermione, Harry, and Ron ventured down to see him immediately even though it was after curfew. Hermione was aghast at the injuries Hagrid had sustained and greatly curious as to his story. Hagrid told the trio about his mission with Madame Maxime to try and recruit the giants in the fight against Voldemort. They were almost caught when Umbridge called on Hagrid that night, but hid under the Invisibilty Cloak. Months later, Hermione and Harry learned why Hagrid was perpetually bruised and cut; he had brought his giant half-brother Grawp back to Hogwarts, as he was getting severely bullied, and was trying to teach him human ways. After Grawp, who had the mental age of a human toddler, picked her up, Hermione forcefully told him to put him down. He subsequently became enamoured with Hermione, calling her "Hermy".

Just after their class took their O.W.Ls, Harry had a vision of his godfather being tortured by Voldemort in the Department of Mysteries. Hermione was worried that it was a trap and convinced Harry to try to contact Sirius before doing anything rash. To that end, she accompanied Harry in an act of solidarity as he sneaked into Umbridge's office to use the Floo Network, with the assistance of Ron, Ginny, and Luna Lovegood, but they were ultimately caught. When Umbridge threatened to use the Cruciatus Curse on Harry during questioning, Hermione interceded. She came up with a lie that she and her fellow D.A. members had been building a weapon for Dumbledore, thus stopping Umbridge's sadistic interrogation and attempted torture of Harry.

Hermione successfully lured Umbridge into the Forbidden Forest by saying that's where the weapon was hidden, where Umbridge was carried away by a herd of centaurs. She had predicted that the centaurs would let her and Harry go, since they did not insult the centaurs and were young enough to be considered "foals". However, the centaurs were already enraged by Umbridge and were further angered when Hermione admitted that she had hoped that they would drive Umbridge off, being insulted that they were thought of to do the bidding of humans. The centaurs were about to carry the two students off as well, but Grawp stumbled onto the scene and a fight broke out between the giant and the herd. This allowed Hermione and Harry to escape and meet up with Ron, Ginny, Luna, and Neville, who had escaped from the Inquisitorial Squad.

Hermione's fear turned out to be justified, as Harry's vision was a ruse planted in his brain by Voldemort designed to lure him to the Ministry to obtain a prophecy Voldemort sought. As soon as Harry did this, the six D.A. members were surrounded by Death Eaters, and a battle ensued. Hermione stunned Nott when he grabbed Harry, thus freeing him and causing Nott to be injured by the collapsing shelves of prophecies. She later stunned another Death Eater and Silenced Antonin Dolohov before he could alert the other Death Eaters to the group's location. She was critically injured by the curse Dolohov subsequently struck her with, but made a full recovery.

Hermione achieved high academic prestige when she obtained ten O.W.L.s, in Charms, Defence Against the Dark Arts, Transfiguration, Care of Magical Creatures, Arithmancy, History of Magic, Herbology, Astronomy, Potions, and Ancient Runes. She received 'Outstanding' marks on each of them, except Defence Against the Dark Arts in which she received an 'Exceeds Expectations,' which she dwelt upon; Ron found it amusing that she actually seemed disappointed by this.

By the time they arrived in Hogwarts, Hermione's romantic feelings for Ron had become obvious. According to Harry the two seemed on their way to a romantic relationship. Hermione and Ron's relationship suffered greatly in their sixth year, when Ron became envious of both Hermione and Harry, who were invited to be members of the Slug Club, a group of students favoured by Potions professor Horace Slughorn, while he was ignored. Hermione strongly disapproved of Harry using the textbook of the "Half-Blood Prince" to get ahead in Potions unfairly, though she did not turn him in and indirectly found a clue about the book owner. She was particularly alarmed by the increasingly Dark nature of the magic in the book, such as the spell Sectumsempra.

However, during an argument with his sister, Ginny humiliated Ron about his inexperience with the opposite gender and told him that Hermione had kissed Viktor Krum during their earlier romance. Ron subsequently began treating Hermione coldly, much to her bewilderment. She was upset when he and Lavender started flirting. When she found out about Ron's relationship with Lavender, she conjured a flock of wild birds to attack Ron for his insensitivity regarding her feelings. He became even angrier with her when she believed that Harry slipped Ron Felix Felicis to assist in his Quidditch-playing abilities; despite having believed it initially himself, he accused her of having no faith in him when it was discovered that he had not been slipped the potion at all. After this, Hermione attended Slughorn's Christmas party with Cormac McLaggen to get back at Ron, but it did not go well due to the former's impoliteness. Afterwards, Ron (who was relieved that Hermione and McLaggen's date did not go well) attempted to speak to Hermione, but she ignored him, still upset and angry over his previous treatment of her.[23] This behaviour presisted for quite sometime.

The two reconciled after Ron was hospitalised due to consuming poisoned mead, an event that left Hermione shaken and frightened. After the incident she remained unusually quiet and subdued. Whilst sitting at Ron's bedside, Ron subconsciously muttered Hermione's name. By this time, Ron was visibly disillusioned with his relationship with Lavender, who had become possessive of him and called him by the annoying nickname "Won-Won." He was also pleased whenever Hermione visited him in the hospital wing. He began avoiding Lavender, who soon became suspicious of his relationship with Hermione, ultimately leading to an argument about her. After Lavender saw Ron and Hermione come down alone from the boys' dormitories (Harry was present also, but under the Invisibility cloak), she had a fight with Ron and broke up with him. When Ron told Harry and Hermione about breaking up with Lavender, Harry could have sworn he saw Hermione smirk.

Afterwards, Hermione and Ron were more comfortable together, and their relationship improved considerably, although a romantic relationship remained out of their reach. Hermione comforted Ron after he failed his Apparition test because he Splinched half an eyebrow, while he teased her about the instructor's praise for her flawless performance. That year, Hermione also quickly mastered non-verbal magic, the first in her class to do so. Throughout the year, Hermione and Ron were both sceptical of Harry's theory that Draco Malfoy had been branded with the Dark Mark and was up to something. Moreover, she was confident that Malfoy couldn't have brought any Dark objects into Hogwarts without alerting Filch. These claims were heard by Draco himself, who used these details and Hermione's previous plan of communication to accomplish his own.

Near the end of the school year, Harry's suspicions would be proven right. Malfoy let Death Eaters into the school by means of a pair of vanishing cabinets. One cabinet resided in Borgin and Burkes and the other in the Room of Hidden Things (as it had been presumed broken, but Malfoy managed to fix it). This infiltration of Death Eaters resulted in the Battle of the Astronomy Tower. Hermione fought in the battle and remained unscathed thanks to some Felix Felicis. This was a gift from Harry, who had won it in a Potions competition and had a preconceived notion of what was going to happen. He told Hermione, Ron, and Ginny to drink it beforehand in case his worries proved true.

Throughout the school year, Hermione and Ron had been informed of the content of Harry's private lessons with Dumbledore. Through these lessons Harry, and in turn Hermione and Ron, learned about the existence of Lord Voldemort's Horcruxes. During the funeral of Albus Dumbledore, who had been killed by Snape in the Battle of the Astronomy Tower, Hermione was comforted by Ron and cried on his shoulder. Afterwards, Harry told them about his desire to drop out of Hogwarts to hunt Horcruxes, which were the key to defeating Lord Voldemort. Despite his protests, Hermione and Ron promised to forgo their seventh year of school in order to assist Harry. Before leaving the school, Hermione was able to Summon books about Horcruxes so as to learn how to destroy the items. She found them in Dumbledore's office, where the late headmaster had kept them after the subject had been banned at Hogwarts.

Hermione began planning for her journey with Harry and Ron immediately. Concerned for the safety of her family, she altered her parents' memories to make them think they were Wendell and Monica Wilkins and sent them to hide in Australia, no longer aware of their original identities, the existence of their daughter, or anything she had told them about Harry. She also withdrew all of her savings at her building society account, in event of a need for Muggle money.

Hermione then joined the Order of the Phoenix in the operation to remove Harry from 4 Privet Drive before his 17th birthday, taking Polyjuice Potion to become one of the "seven Potters". Hermione flew on a Thestral with Kingsley Shacklebolt. The two fought off at least five Death Eaters, possibly killing one, injuring two, and were pursued by Lord Voldemort himself at one point. In time, they arrived safely at the Burrow, where Hermione was immensely relieved to see Harry alive and ran to him and hugged him tight, but she was greatly worried when Ron did not show up on time. When he landed, she ran and nuzzled him in relief. She was saddened by the news of Alastor Moody and Hedwig's murders and disturbed by Harry's vision of Garrick Ollivander being tortured.

Later on, the Minister for Magic, Rufus Scrimgeour, interrupted Harry's birthday celebrations to execute Albus Dumbledore's will and bequeath some of his belongings to the three friends. Hermione received The Tales of Beedle the Bard , a book of children's stories written in runes. Even before Hermione understood the priceless quality of the gift, she was moved to tears by Dumbledore's great act of friendship. During the reading of Dumbledore's will, she also displayed her incredible store of general knowledge when she mentioned that "Snitches have flesh memories," surprising both Ron and Harry, who had both believed her to know little to nothing of Quidditch.

At Bill Weasley and Fleur Delacour's wedding on 1 August, 1997, Hermione wore a "floaty, lilac-coloured dress with matching high heels" and made her hair "sleek and shiny." She was amused by Fred and George's stories about their late uncle Bilius and shared a friendly exchange with Viktor Krum, to the frustration of Ron. She was happily surprised when Ron quickly asked her to dance, and when Krum asked a disguised Harry whether the two were together, Harry replied "Er... sort of."

The wedding was interrupted by Kingsley Shacklebolt's Patronus who told the guests of the fall of the Ministry of Magic. Hermione was prepared to make a quick escape, immediately Disapparating herself, Harry, and Ron away from the danger. Hermione also showed great foresight and magical talent when she revealed a small beaded purse on which she had placed an Undetectable Extension Charm. Within it she had packed, amongst other things, clothing, a tent, healing supplies, Harry's Invisibility Cloak, and several useful books. They arrived on the Muggle street, Tottenham Court Road, where Hermione suggested they enter a café, as a means to get out of the open.

However, minutes later Hermione unknowingly triggered the Taboo curse that was placed on Voldemort's name, and the trio were thus tracked down by Antonin Dolohov and Thorfinn Rowle. After a brief but violent skirmish, the Death Eaters were subdued, and Hermione modified their memories to throw them off the scent and to maintain Ron's cover story that he was sick with spattergroit and bedridden at home. At Harry's suggestion the three then made their way safely to 12 Grimmauld Place, as they could not hide anywhere within the wizarding world.