The Academy Award for Best Actress is an award presented annually by the Academy of Motion Picture Arts and Sciences (AMPAS). It is given in honor of an actress who has delivered an outstanding performance in a leading role while working within the film industry. The 1st Academy Awards ceremony was held in 1929 with Janet Gaynorreceiving the award for her roles in 7th Heaven, Street Angel, and Sunrise.^[1] Currently, nominees are determined bysingle 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, actresses 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.^[3] 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.^[4] The following year, this unwieldy and confusing system was replaced by the current system in which an actress is nominated for a specific performance in a single film.^[3] Starting with the 9th ceremony held in 1937, the category was officially limited to five nominations per year.^[3]

Since its inception, the award has been given to 73 actresses. Katharine Hepburn has won the most awards in this category, with four Oscars. Meryl Streep has been nominated on 15 occasions (resulting in two awards), more than any other actress. As of the 2015 ceremony, Julianne Moore is the most recent winner in this category for her role as Alice Howland in Still Alice

Julianne Moore