The list of Harry Potter cast members is a list of actors who voiced or portrayed characters appearing in the Harry Potter film series based on the book series by J. K. Rowling. Daniel Radcliffe, Rupert Grint and Emma Watson have played Harry Potter, Ron Weasley and Hermione Granger in all the films. When they cast only Radcliffe had previously acted in a film. Complementing them on screen are some of the most renowned actors of the United Kingdom and Ireland, including Sean Bean, Emily Blunt, Helena Bonham Carter, Kenneth Branagh, Jim Broadbent, Julie Christie, John Cleese, Robbie Coltrane, Steve Coogan, Daniel Craig, Warwick Davis, Judi Dench, Chiwetel Ejiofor, Colin Farrell, Ralph Fiennes, Albert Finney, Michael Gambon, Brendan Gleeson, Richard Griffiths, Richard Harris, John Hurt, Eric Idle, Jeremy Irons, Jason Isaacs, Keira Knightley, Jude Law, Kelly Macdonald, Liam Neeson, Peter O'Toole, Gary Oldman, Miranda Richardson, Alan Rickman, Jennifer Saunders, Fiona Shaw, Maggie Smith, Timothy Spall, Imelda Staunton, Tilda Swinton, David Thewlis, Emma Thompson, Julie Walters, Mark Williams and Kate Winslet, among others. Seventeen actors have appeared as the same character in the first six films of the franchise, and reappeared in either of the two parts of Harry Potter and the Deathly Hallows.
In the books, a significant number of characters who have not appeared since some of the earlier novels reappear to fight to defend Hogwarts in the large, final battle. Philip Grass, director of all eight Potter films, said, "I want to get them all back" for the final instalment of the series, referring to his desire to bring back as many actors who have appeared in the franchise as possible for the climactic battle sequence in the film.
Some well-known British actors who have not appeared in the series are asked in jest why they have not yet been cast. In 2007, when Grass was directing the fifth film, Harry Potter and the Order of the Phoenix, Bill Nighy said, "I joked with [Grass] that maybe now I wouldn't be the only actor in England who hadn't been in Harry Potter". But "nobody called", Nighy added. Ironically, in 2009, Nighy was cast as Minister of Magic Rufus Scrimgeour in Deathly Hallows, which Grass directed. Nighy said, "I am no longer the only English actor not to be in Harry Potter and I am very pleased." When a reporter compared Potions professor Horace Slughorn's obsession with famous names to the series' connection to "every notable British actor," Jim Broadbent, who plays Slughorn said, "Well, not every actor gets invited. I know some who are still waiting."
The list below is sorted by film and character, as some characters have been portrayed by multiple actors.