Harry Potter (DANIEL RADCLIFFE) is an 11-year-old boy who's forced to live under the stairs in the home of his mean-spirited aunt and uncle, Vernon (RICHARD GRIFFITHS) and Petunia Dursley (FIONA SHAW) and their spoiled son, Dudley (HARRY MELLING). Told that his parents died in a car crash when he was an infant, Harry has never known the love of family, and is mistreated by his relatives who seem suspicious of him and his abilities.
In reality, Harry is a wizard who was placed in the home by Professor Dumbledore (RICHARD HARRIS) and Professor McGonagall (MAGGIE SMITH). They are two veteran wizards who run Hogwarts, a boarding school for sorcerers, and initially wanted to keep the boy away from the evil wizard Voldemort who killed his parents.
Now, however, the time has come for Harry to attend Hogwarts, so Rubeus Hagrid (ROBBIE COLTRANE), the school's giant groundskeeper, retrieves the boy, equips him with everything he'll need for his new education, and sends him off. En route to Hogwarts, Harry meets other new students including Ron Weasley (RUPERT GRINT) and Hermione Granger (EMMA WATSON), and the three quickly become fast friends.
Upon their arrival, the three meet other students, such as elitist Draco Malfoy (TOM FELTON), and learn the rules of the school as they're assigned to one of Hogwarts' four schools. As they attend various classes and activities taught by the likes of Professor Snape (ALAN RICKMAN), Professor Quirrell (IAN HART) and Madam Hooch (ZOË WANAMAKER) and meet the schools' various oddities such as the ghostly Nearly Headless Nick (JOHN CLEESE), the kids learn more about the school and how to perform magic.
While doing so, Harry and his friends become suspicious of some mysterious occurrences and behavior. That all leads up to them learning about the Sorcerer's Stone, a small rock with magical powers that can turn any metal into gold and creates the elixir of life that insures immortality. As the three dig deeper into the mystery, they must deal with various adventures and menacing figures, all while trying to get through their first year at Hogwarts.