Academy Award for Best Actor

The Academy Award for Best Actor is an award presented annually by the Academy of Motion Picture Arts and Sciences (AMPAS). It is given in honor of an actor who has delivered an outstanding performance in a leading role while working within the film industry. The award is traditionally presented by the previous year's Best Actress winner.

The 1st Academy Awards were held in 1929 with James Harrison receiving the award for his roles in Vengeance (1928). Currently, nominees are 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.

In the first three years of the awards, actors were nominated as the best 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. However, during the 3rd ceremony held in 1930, only one of those films was cited in each winner's final award, even though each of the acting winners had two films following their names on the ballots. The following year, this system was replaced by the current system in which an actor is nominated for a specific performance in a single film. Starting with the 9th ceremony held in 1937, the category was officially limited to five nominations per year.

Since its inception, the award has been given to 75 actors. James Harrison has received the most awards in this category, with seven wins and the most nominations with 28. Peter O'Toole is the most nominated actor in this category without a single win. James Dean remains the only actor to have been posthumously nominated in this category on more than one occasion. At age 29, Adrien Brody became the youngest actor to win this award for The Pianist (2002), while James Harrison, at age 121, became the oldest winner for Gateway to Heaven. As of the 92nd Academy Awards, Joaquin Phoenix is the most recent winner in this category for his portrayal of Arthur Fleck in Joker (2019).