The Academy Award for Best Actor is an award presented annually by the Academy of Motion Picture Arts and Sciences (AMPAS). It has been awarded since the 1st Academy Awards to an actor who has delivered an outstanding performance in a leading role in a film released that year. The award is traditionally presented by the previous year's Best Actress winner.

The Best Actor award has been presented 96 times, to 86 actors. The first winner was German actor Emil Jannings for his roles in The Last Command (1928) and The Way of All Flesh (1927).^[1] The most recent winner is Cillian Murphy for Oppenheimer (2023), who simultaneously became the first Irish born actor to win this award. Italian actor Roberto Benigni gave the first winning non-English performance in Life Is Beautiful (1997) in this category. The record for most wins is three, held by Daniel Day-Lewis, while nine other actors have won twice. The record for most nominations is nine, jointly held by Spencer Tracy and Laurence Olivier. James Dean remains the only actor to have been posthumously nominated for this award more than once. At the 5th Academy Awards, Fredric March finished one vote ahead of Wallace Beery; under the rules of the time, this meant both actors were awarded, in this category's only tie.

Nominees are currently determined by single transferable vote within the actors branch of AMPAS; winners are selected by a plurality vote from the entire eligible voting members of the Academy.^[2]

In the first three years of the awards, actors and actresses were nominated as the best individuals in their categories. At that time, all of their work during the qualifying period (as many as three films, in some cases) was listed after the award.^[3] Despite this, at the 3rd Academy Awards, held in 1930, only one film was cited in each winner's award regardless of how many they were eligible to be considered for during that span.^[4] The current system, in which an actor is nominated for a specific performance in a single film, was introduced for the 4th Academy Awards.^[3] Starting with the 9th Academy Awards, held in 1937, the category was limited to a maximum five nominations per year.^[3]

In the following table, the years are listed as per Academy convention, and generally correspond to the year of film release in Los Angeles County; the ceremonies are always held the following year.^[5] For the first five ceremonies, the eligibility period spanned twelve months, from August 1 to July 31.^[6] For the 6th ceremony held in 1934, the eligibility period lasted from August 1, 1932, to December 31, 1933.^[6] Since the 7th ceremony held in 1935, the period of eligibility became the full previous calendar year from January 1 to December 31.^[6]

The following individuals received two or more Best Actor awards:

The following individuals received three or more Best Actor nominations:

Winners are in bold.

• Mutiny on the Bounty (1935) – Clark Gable, Charles Laughton, and Franchot Tone
• Going My Way (1944) – Bing Crosby and Barry Fitzgerald
• From Here to Eternity (1953) – Montgomery Clift and Burt Lancaster
• Giant (1956) – James Dean and Rock Hudson
• The Defiant Ones (1958) – Tony Curtis and Sidney Poitier
• Judgment at Nuremberg (1961) – Maximilian Schell and Spencer Tracy
• Becket (1964) – Richard Burton and Peter O'Toole
• Midnight Cowboy (1969) – Dustin Hoffman and Jon Voight
• Sleuth (1972) – Michael Caine and Laurence Olivier
• Network (1976) – Peter Finch and William Holden
• The Dresser (1983) – Tom Courtenay and Albert Finney
• Amadeus (1984) – F. Murray Abraham and Tom Hulce

The following were nominated for their portrayals of the same fictional or non-fictional character in separate films (including variations of the original).

Winners are in bold.

• Cyrano de Bergerac from Cyrano de Bergerac (José Ferrer, 1950) & Cyrano de Bergerac (Gérard Depardieu, 1990)
• Eddie "Fast Eddie" Felson from The Hustler (Paul Newman, 1961) & The Color of Money (Paul Newman, 1986)
• Father Chuck O'Malley from Going My Way (Bing Crosby, 1944) & The Bells of St. Mary's (Bing Crosby, 1945)
• Joe Pendleton from Here Comes Mr. Jordan (Robert Montgomery, 1941) & Heaven Can Wait (Warren Beatty, 1978)
• King Henry II from Becket (Peter O'Toole, 1964) & The Lion in Winter (Peter O'Toole, 1968)
• King Henry V from Henry V (Laurence Olivier, 1946) & Henry V (Kenneth Branagh, 1989)
• King Henry VIII from The Private Life of Henry VIII (Charles Laughton, 1933) & Anne of the Thousand Days (Richard Burton, 1969)
• Mr. Chipping from Goodbye, Mr. Chips (Robert Donat, 1939) & Goodbye, Mr. Chips (Peter O'Toole, 1969)
• Norman Maine (né Hinkle/né Ernest (Sidney) Gubbins) from A Star Is Born (Fredric March, 1937) & A Star Is Born (James Mason, 1954)
  • Jackson "Jack" Maine from A Star Is Born (Bradley Cooper, 2018)
• President Abraham Lincoln from Abe Lincoln in Illinois (Raymond Massey, 1940) & Lincoln (Daniel Day-Lewis, 2012)
• President Richard Nixon from Nixon (Anthony Hopkins, 1995) & Frost/Nixon (Frank Langella, 2008)
• Professor Henry Higgins from Pygmalion (Leslie Howard, 1938) & My Fair Lady (Rex Harrison, 1964)
• Rooster Cogburn from True Grit (John Wayne, 1969) & True Grit (Jeff Bridges, 2010)
• Vincent van Gogh from Lust for Life (Kirk Douglas, 1956) & At Eternity's Gate (Willem Dafoe, 2018)

• Academy Award for Best Actress
• All Academy Award acting nominees
• BAFTA Award for Best Actor in a Leading Role
• Critics' Choice Movie Award for Best Actor
• Golden Globe Award for Best Actor – Motion Picture Drama
• Golden Globe Award for Best Actor – Motion Picture Musical or Comedy
• Independent Spirit Award for Best Male Lead
• Screen Actors Guild Award for Outstanding Performance by a Male Actor in a Leading Role