The Acorn Stakes is an American Grade I race at Belmont Park in Elmont, New York for three-year-old Thoroughbred fillies. It is raced on dirt over a distance of one mile with a current purse of $750,000. It is the first leg of the US Triple Tiara and is followed by the Coaching Club American Oaks then the Alabama Stakes. The filly must win all three races to win the Triple Tiara.The Acorn Stakes was run at Aqueduct Racetrack from 1960 to 1967 and 1969 to 1975.