Arthur Bowen

Several actors of the United Kingdom and Ireland have 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 were cast only Radcliffe had previously acted in a film. Complementing them on screen are such actors as Helena Bonham Carter, Jim Broadbent, John Cleese, Robbie Coltrane, Warwick Davis, Ralph Fiennes, Michael Gambon, Brendan Gleeson, Richard Griffiths, Richard Harris, John Hurt, Jason Isaacs, Miriam Margolyes, Helen McCrory, Gary Oldman, Alan Rickman, Fiona Shaw, Maggie Smith, Timothy Spall, Imelda Staunton, David Thewlis, Emma Thompson, and Julie Walters, among others. Thirteen actors have appeared as the same character in all eight films of the series.

Some well-known British actors, who have not appeared in the series, were asked in jest why they had not been cast. When David Yates was directing the fifth film, Bill Nighy (who knew Yates personally) said that he hoped the director would cast him in Harry Potter. "But nobody called", Nighy added. However, in 2009, Yates cast Nighy as Minister of Magic Rufus Scrimgeour in the seventh film. Nighy said, "I am no longer the only English actor not to be in Harry Potter and I am very pleased." Jude Law once quipped, "Nobody's asked me. I was a bit too old for Harry." When a reporter compared Potions professor Horace Slughorn's obsession with famous names to the series' connection to "every notable British actor" in 2009, Jim Broadbent (who plays Slughorn) said, "Well, not every actor gets invited. I know some who are still waiting."

J.K. Rowling gave a speech during the world premiere of the final film in the series, Harry Potter and the Deathly Hallows – Part 2, on 7 July 2011 in London. Rowling praised the film series' acting talent and announced that there are seven young Harry Potter cast members who she refers to as "The Big Seven"; they are Daniel Radcliffe, Rupert Grint, Emma Watson, Tom Felton, Matthew Lewis, Evanna Lynch and Bonnie Wright.

The list below is sorted by film and character since some characters have been portrayed by multiple actors.

Key

• (v) indicates the actor or actress lent only his or her voice for his or her film character
• (y) indicates the actor or actress portrayed the role in a flashback scene or when the character was young.
• (f) indicates the actor or actress did not appear in any new footage for the film; footage from an earlier film or films was used.
• A light grey cell (such as the one in the "Charity Burbage" row in the "Philosopher's Stone" column) indicates the character was not in the film adaptation.