Late one night, Albus Dumbledore and Minerva McGonagall, professors at Hogwarts School of Witchcraft and Wizardry, along with groundskeeper Rubeus Hagrid, deliver an orphaned infant wizard named Harry Potter to his Muggle aunt and uncle, Petunia and Vernon Dursley, his only living relatives.

Ten years later, just before Harry's eleventh birthday, owls begin delivering letters addressed to him. When the abusive Dursleys adamantly refuse to allow Harry to open any and flee to an island hut, Hagrid arrives to personally deliver Harry's letter of acceptance to Hogwarts. Hagrid also reveals that Harry's parents, James and Lily, were killed by a dark wizard named Lord Voldemort. The killing curse that Voldemort had cast rebounded, destroying Voldemort's body and giving Harry his lightning-bolt scar. Hagrid then takes Harry to Diagon Alley for school supplies and gives him a pet snowy owl whom he names Hedwig. Harry buys a wand that is connected to Voldemort's own wand.

At King's Cross station, Harry boards the Hogwarts Express train, and meets fellow students Ron Weasley and Hermione Granger during the journey. Arriving at Hogwarts, Harry also meets Draco Malfoy, who is from a wealthy wizard family; the two immediately form a rivalry. The students assemble in the Great Hall where the Sorting Hat sorts the first-years into four respective houses: Gryffindor, Hufflepuff, Ravenclaw, and Slytherin. Harry is placed into Gryffindor alongside Ron and Hermione, while Draco is placed into Slytherin, a house noted for dark wizards.

As Harry studies magic, he learns more about his parents and Voldemort. Harry's natural talent for broomstick flying gets him recruited as the youngest-ever Seeker for Gryffindor's Quidditch team in a century. While returning to the Gryffindor common room, the staircases change paths, leading Harry, Ron, and Hermione to the third floor, which is forbidden to students. There they discover a giant three-headed dog named Fluffy. On Halloween, Ron insults Hermione after she shows off in Charms class; upset, she spends the afternoon crying in the girls' bathroom. That evening, a giant marauding troll enters it, but Harry and Ron save Hermione, and the three make up and become close friends after Hermione takes the blame for the incident by claiming she went looking for the troll.

The trio discover that Fluffy is guarding the philosopher's stone, a magical object that can turn metal into gold and produce an immortality elixir. Harry suspects that Potions teacher and head of Slytherin House, Severus Snape, wants the stone to return Voldemort to physical form. When Hagrid accidentally reveals that music puts Fluffy asleep, Harry, Ron and Hermione decide to find the stone before Snape. Fluffy is already asleep, but the trio face other barriers, including a deadly plant called Devil's Snare, a room filled with aggressive flying keys, and a giant chess game that knocks out Ron.

After overcoming the barriers, Harry encounters Defence Against the Dark Arts teacher Quirinus Quirrell who wants the stone; Snape had figured it out and had been protecting Harry. Quirrell removes his turban to reveal a weakened Voldemort living on the back of his head. Dumbledore's protective enchantment places the stone in Harry's possession. Voldemort attempts to bargain the stone from Harry in exchange for resurrecting his parents, but Harry sees through his trick and refuses. Quirrell attempts to kill Harry. When Harry touches Quirrell's skin, it burns Quirrell, reducing him to ashes. Voldemort's soul rises from the pile and escapes, knocking out Harry as it passes through him.

Harry recovers in the school infirmary. Dumbledore tells him the stone has been destroyed to prevent misuse, and that Ron and Hermione are safe. He also reveals how Harry defeated Quirrell: when Lily died to save Harry, a love-based protection against Voldemort was placed on him. Harry, Ron, and Hermione are rewarded with house points for their heroism, tying Gryffindor for first place with Slytherin. Dumbledore then awards ten points to their housemate Neville Longbottom for having had the courage to stand up to the trio, granting Gryffindor the House Cup. Harry returns to the Dursleys for the summer, happy to finally have a real home at Hogwarts.

Plot

Harry Potter lives with his abusive aunt and uncle, Vernon and Petunia Dursley, and their bullying son, Dudley. On Harry's eleventh birthday, a half-giant named Rubeus Hagrid personally delivers an acceptance letter to Hogwarts School of Witchcraft and Wizardry, revealing that Harry's parents, James and Lily Potter, were wizards. When Harry was one year old, an evil and powerful dark wizard, Lord Voldemort, murdered his parents. Harry survived Voldemort's killing curse that rebounded and seemingly destroyed the Dark Lord, leaving a lightning bolt-shaped scar on his forehead. Unknown to Harry, this act made him famous in the wizarding world.

Hagrid escorts Harry to Diagon Alley, the hidden wizard commerce and retail section in London. Harry's parents have left him a fortune kept in Gringotts Wizarding Bank, which he uses to buy school supplies and a wand from Ollivander's. The cores of Harry and Lord Voldemort's wands have feathers from the same phoenix bird, making them "brothers". Hagrid gifts Harry an owl as a birthday present. Harry names her Hedwig. A month later, Harry boards the Hogwarts Express at King's Cross railway station's secret Platform 9¾. On the journey to Hogwarts, Harry befriends fellow first year Ron Weasley and meets Hermione Granger, whom the two boys initially dislike.

Harry runs afoul of Draco Malfoy, the spoiled son of a prominent wizard. At Hogwarts, a magical Sorting Hat sorts the first years among four school Houses (Gryffindor, Hufflepuff, Ravenclaw, and Slytherin) that best suit their personalities and talents. Draco joins Slytherin, known for producing dark wizards, while Harry, Ron, and Hermione are sorted into Gryffindor.

Harry's broomstick flying ability earns him a place on the Gryffindor Quidditch team as the Seeker. Harry comes to dislike Potions master Severus Snape, who favours Slytherin while seeking to fail Harry. Malfoy tricks Harry and Ron into risking expulsion by leaving their common room after curfew. Hermione, unable to stop them, tags along. Realising Malfoy's ruse, they hide in a forbidden corridor and discover a gigantic three-headed dog guarding a trapdoor. Harry and Ron later save Hermione from a troll during the school's Halloween celebration and the three become best friends. Coupled with Snape's recent leg injury and suspicious behaviour, Harry, Ron, and Hermione believe he is attempting to enter the trapdoor.

Hermione warns the boys against investigating further and instead directs Harry's attention to his first Quidditch match. His broomstick's attempts to buck him off and Snape's strange behaviour during the match convinces Hermione he jinxed Harry's broom. Harry receives an anonymous Christmas gift – his father's invisibility cloak. Using it to explore the school, he discovers the Mirror of Erised, which shows what the viewer most desires. Harry sees his parents.

The trio read a newspaper report about an attempted robbery at Gringotts Bank and the same vault from which Hagrid retrieved an item for the school's headmaster Albus Dumbledore on the same day. They suspect the object beneath the trapdoor is the philosopher's stone, which grants its user immortality and the ability to turn any metal into pure gold. A forest centaur named Firenze warns Harry that Voldemort is plotting to steal the stone to restore his body. When Dumbledore is lured from Hogwarts under false pretences, Harry, Hermione, and Ron fear the theft is imminent and descend through the trapdoor.

A series of obstacles force Ron and Hermione to remain behind while Harry proceeds. Harry encounters Professor Quirrell, the Defence Against the Dark Arts teacher, who reveals that he jinxed Harry's broom and let the troll into the school; Snape was protecting Harry. Voldemort, whose face has slowly regrown on the back of Quirrell's head, is revealed to be the professor's secret master. Harry is forced to stand before the Mirror of Erised. It recognises Harry's lack of greed for the stone and deposits it into his pocket. Quirrell attempts to seize the stone, but his flesh burns upon contact with Harry. Harry's scar begins hurting and he passes out.

Harry awakens in the school's infirmary. Dumbledore explains Harry survived Voldemort because his mother sacrificing her life for him left a magical protective charm. Quirrell's hatred and greed caused him to burn upon contact with Harry; Voldemort abandoned him to die. Dumbledore reveals he sent Harry the invisibility cloak, while the philosopher's stone, that had been keeping the long-lived Nicolas Flamel alive, has been destroyed with Flamel's consent to prevent its being stolen. During the school's year-end feast, Gryffindor is awarded the House Cup. Harry returns to the Dursleys at Privet Drive until the next school year.

Characters

• Harry Potter is an orphan whom Rowling imagined as a "scrawny, black-haired, green eyed and bespectacled boy who didn't know he was a wizard."[3] She developed the series' story and characters to explain how Harry came to be in this situation and how his life unfolded from there.[4] Apart from the first chapter, the events of this book take place just before and in the year following Harry's eleventh birthday. Voldemort's attack left a lightning bolt-shaped scar on Harry's forehead,[4] which produces stabbing pains whenever Voldemort is present. Harry has a natural talent for Quidditch and became the first person in a century to get on their team in their first year.
• Ron Weasley is Harry's age, and Rowling describes him as the ultimate best friend "always there when you need him."[5] He is freckled, red-haired, and quite tall. He grew up in a fairly large pure-blood family as the sixth born of seven children. Although his family is quite poor, they still live comfortably and happily. His loyalty and bravery in the face of a game of Wizards Chess plays a vital part in finding the Philosopher's Stone.
• Hermione Granger, the daughter of an all-Muggle family, is a bossy girl who has apparently memorised most of the textbooks before the start of term. Rowling described Hermione as a "very logical, upright and good" character with "a lot of insecurity and a great fear of failure beneath her swottiness".[6] Despite her nagging efforts to keep Harry and Ron out of trouble, she becomes a close friend of the two boys after they save her from a troll and her magical and analytical skills play an important role in finding the Philosopher's Stone. She has bushy brown hair and rather large front teeth.
• Neville Longbottom is a plump, diffident boy, so forgetful that his grandmother gives him a Remembrall, to remind him if he forgets something. Neville's magical abilities are weak and appeared just in time to save his life when he was eight. Despite his timidity, Neville will fight anyone after some encouragement or if he thinks it is right and important.
• Rubeus Hagrid, a half-giant nearly 12 feet (3.7 m) tall, with tangled black hair and beard, was expelled from Hogwarts and his wand was snapped in half (resulting in him never to use a wand again), however Professor Dumbledore let him stay on as the school's gamekeeper, a job which enables him to give lavish affection, care and even pet names (such as Norbert the dragon) on even the most dangerous of magical creatures. Hagrid is fiercely loyal to Dumbledore and quickly becomes a close friend of Harry, Ron and, later, Hermione, but his carelessness makes him unreliable.
• Professor Albus Dumbledore, a tall, thin man who wears half-moon spectacles and has silver hair and a beard that tucks into his belt, is the headmaster of Hogwarts, and thought to be the only wizard Voldemort fears. Dumbledore, while renowned for his achievements in magic, shrugs off praise, though he is aware of his own brilliance. Rowling described him as the "epitome of goodness".[7]
• Professor Minerva McGonagall, a tall, severe-looking woman with black hair tied in a tight bun, teaches Transfiguration and is able to transform herself into a cat. She is Deputy Headmistress and Head of Gryffindor House.
• Petunia Dursley, the sister of Harry's mother Lily, is a thin woman with a long neck that she uses for spying on the neighbours. As a muggle, she regards her magical sister as a freak and tries to pretend that she never existed.
• Vernon Dursley, the husband of Petunia Dursley, is a heavily built man whose irascible bluster covers a narrow mind and a fear of anything unusual.
• Dudley Dursley is an overweight, spoilt bully and Harry's cousin.
• Draco Malfoy is a slim, pale boy who speaks in a bored drawl. He is arrogant about his skill in Quidditch, and despises anyone who is not a pure-blood wizard  and wizards who do not share his views. His parents had supported Voldemort, but changed sides after the dark wizard's disappearance, claiming they had been bewitched. Draco avoids direct confrontations and tries to get Harry and his friends into trouble.
• Oliver Wood is Harry's Quidditch captain and keeper for the Gryffindor Quidditch team.
• Professor Quirrell is a twitching, stammering, and nervous man who teaches Defence Against the Dark Arts. Reputedly he was a brilliant scholar, but his nerve was shattered by an encounter with vampires. Quirrell wears a turban to conceal the fact that he is voluntarily possessed by Voldemort, whose face appears on the back of Quirrell's head.
• Professor Severus Snape, who has a hooked nose, sallow complexion, and greasy black hair, teaches Potions, but would prefer to teach Defence Against the Dark Arts. Snape favours pupils in Slytherin, his own House and seizes every opportunity to humiliate others, especially Harry. Several incidents, beginning with the shooting pain in Harry's scar during the start-of-term feast, lead Harry and his friends to think Snape is aiding Voldemort.
• Argus Filch, the school caretaker who knows the school's secret passages better than anyone else except, perhaps, the Weasley twins. His cat, Mrs. Norris, aids his constant hunt for misbehaving pupils.

Other members of staff include: the dumpy Herbology teacher and Head of Hufflepuff House Professor Sprout, Professor Flitwick, the tiny and excitable Charms teacher and Head of Ravenclaw House, the soporific History of Magic teacher, Professor Binns, a ghost who does not seem to have noticed his own death, and Madam Hooch, the Quidditch coach, who is strict, but a considerate and methodical teacher. The poltergeist Peeves wanders around the castle causing trouble wherever he can.

In the book, Rowling introduces an eclectic cast of characters. The first character to be introduced is Vernon Dursley, Harry's uncle. Most of the actions centre on the eponymous hero Harry Potter, an orphan who escapes his miserable childhood with the Dursley family. Rowling imagined him as a "scrawny, black-haired, bespectacled boy who didn't know he was a wizard"[3] and says she transferred part of her pain about losing her mother to him.[8] During the book, Harry makes two close friends, Ronald Weasley and Hermione Granger. Ron is described by Rowling as the ultimate best friend, "always there when you need him".[5] Rowling has described Hermione as a "very logical, upright and good" character with "a lot of insecurity and a great fear of failure beneath her swottiness".[6]

Rowling also imagined a supporting cast of adults. The headmaster of Hogwarts is the powerful, but kind wizard Albus Dumbledore, who becomes Harry's confidant. Rowling described him as "the epitome of goodness".[7] His right hand is severe Minerva McGonagall, the friendly half-giant Rubeus Hagrid, who saved Harry from the Dursley family and the sinister Severus Snape. Professor Quirrell is also featured in the novel.

The main antagonists are Draco Malfoy, an elitist, bullying classmate,[9] and Lord Voldemort, the most powerful evil wizard who becomes disembodied when he tries to kill baby Harry. According to a 1999 interview with Rowling, the character of Voldemort was created as a literary foil for Harry and his backstory was intentionally not fleshed-out at first:

The basic idea... Harry, I saw Harry very very very clearly. Very vividly. And I knew he didn't know he was a wizard. ... And so then I kind of worked backwards from that position to find out how that could be, that he wouldn't know what he was. ... When he was one year old, the most evil wizard for hundreds and hundreds of years attempted to kill him. He killed Harry's parents, and then he tried to kill Harry—he tried to curse him. ... And—so—but for some mysterious reason, the curse didn't work on Harry. So he's left with this lightning bolt shaped scar on his forehead and the curse rebounded upon the evil wizard, who has been in hiding ever since.[4]