Lord Voldemort, an evil and powerful dark wizard, has just been defeated. When he tried to kill a one-year old child, Harry Potter, the killing curse rebounded upon him, destroying his body. Harry is left an orphan with a lightning-bolt scar on his forehead, Voldemort having killed his parents, Lily and James Potter. Professors Dumbledore and McGonagall and Gamekeeper Hagrid leave him on the doorstep of his ultra-conventional, insensitive, negligent Muggle (non-magical) relatives, the Dursley family, who take him in. Harry's aunt, Petunia Dursley, was Harry's mother Lily's sister. Harry's relatives decide to conceal his magical heritage from him and make him live in a cupboard (closet) under the stairs for ten years.

Shortly before Harry's eleventh birthday, he receives a letter addressed specifically to him. His outraged uncle, however, reads and burns it before Harry has a chance to look at the contents. The sender does not give up, and the Dursleys receive successively larger numbers of the same correspondence. Soon, his uncle becomes so paranoid that the Dursleys, with Harry in tow, hide in a hut on a small island to escape. That night (which happens to be Harry's birthday), he is visited by an enormous man named Hagrid who bursts through the locked door of the hut. With Hagrid holding the Dursleys at bay, Harry finally reads his letter, in which he learns he has been invited to study magic at Hogwarts School of Witchcraft and Wizardry. The next day Harry and Hagrid leave the hut and head to Diagon Alley in London (the secret magical location hidden behind the famous wizarding pub The Leaky Cauldron). Harry enters the wizarding world for the first time, learns to his surprise that he is famous, and meets the new Hogwarts Defence Against the Dark Arts teacher, Professor Quirrell. He takes the train to Hogwarts from Platform Nine and three-quarters, befriending Ron Weasley, and meeting Neville Longbottom, a frightfully forgetful boy, and Hermione Granger, a Muggle-born witch.