The following events occurred in the year 1991:
- 1 Events
- 2 Deaths
- 3 Behind the scenes
- 4 See also
- 5 Notes and references
- Harry Potter finishes at his Muggle Primary School, at the age of ten.
- Charlie Weasley and Nymphadora Tonks graduate from Hogwarts School of Witchcraft and Wizardry.
- A Wizardry Budget is leaked and makes Daily Prophet headlines.
- 23 June: For Dudley Dursley's eleventh birthday, his parents, cousin Harry Potter, and Piers Polkiss go to the zoo. Harry speaks Parseltongue for the first time to a boa constrictor.
- 24 July: Harry Potter receives his first Hogwarts letter. Vernon and Petunia Dursley burn it. Harry's bedroom is moved from the Cupboard under the stairs to Dudley's second bedroom.
- 31 July: Quirinus Quirrell breaks into Gringotts Wizarding Bank, but fails to steal the Philosopher's Stone. Harry, on his eleventh birthday, goes to Diagon Alley for the first time with Rubeus Hagrid.
- 1 September: Harry Potter and his classmates – including Ron Weasley, Hermione Granger, Neville Longbottom, and Draco Malfoy – begin at Hogwarts.
- 12 September: Harry Potter becomes the youngest Seeker in a century for the Gryffindor Quidditch team.
- 31 October: During the Halloween feast at Hogwarts, a mountain troll is let loose by Professor Quirrell, who looks for the Philosopher's Stone. Harry Potter and Ron Weasley save Hermione Granger from the troll, and the three become friends. 
- 25 December: Harry receives his late father's Invisibility Cloak from Albus Dumbledore as a Christmas present. He also finds the Mirror of Erised and sees his family for the first time.
Individuals that started at Hogwarts
- Lavender Brown
- Hermione Granger 
- Neville Longbottom 
- Parvati Patil
- Harry Potter 
- Dean Thomas
- Ronald Weasley 
- Hannah Abbott 
- Susan Bones 
- Justin Finch-Fletchley 
- Wayne Hopkins 
- Megan Jones 
- Ernie Macmillan 
- Terry Boot
- Mandy Brocklehurst 
- Michael Corner 
- Anthony Goldstein 
- Sue Li 
- Morag MacDougal
- Padma Patil
- Lisa Turpin 
- Millicent Bulstrode 
- Vincent Crabbe 
- Tracey Davis 
- Gregory Goyle 
- Daphne Greengrass
- Draco Malfoy 
- Theodore Nott 
- Pansy Parkinson 
- Blaise Zabini 
- Stephen Cornfoot (Hufflepuff or Ravenclaw)
- Kevin Entwhistle (Hufflepuff or Ravenclaw)
- Roger Malone (Hufflepuff or Ravenclaw)
- Lily Moon (Hufflepuff or Slytherin)
- Oliver Rivers (Hufflepuff or Ravenclaw)
- Sally-Anne Perks (Gryffindor, Hufflepuff or Slytherin)
- Sophie Roper (Gryffindor, Hufflepuff or Slytherin)
- Runcorn (Gryffindor, Hufflepuff or Slytherin)
- Sally Smith (Gryffindor, Hufflepuff or Slytherin)
Individuals who gathered from Hogwarts
Behind the scenes
- 17 February: Bonnie Wright, the actress who portrays Ginny Weasley in the Harry Potter films, is born.
- April 21: Frank Dillane, the actor who portrays young Tom Riddle in the film adaptation of Harry Potter and the Half-Blood Prince, is born.
- 16 August: Evanna Lynch, the actress who portrays Luna Lovegood in the Harry Potter films, is born.
- 18 October: Toby Regbo, the actor who portrays a Young Albus Dumbledore in the Harry Potter films is born.
- 13 January: Genevieve Gaunt, the actress who portrays Pansy Parkinson in the film adaptation of Harry Potter and the Prisoner of Azkaban, is born.