Grace Leboy Kahn (September 22, 1890 – May 24, 1983) was an American composer. A prolific songwriter, among her best known works are "I Wish I Had A Girl" (1908) and selections from the Jumping Jupiter musical.
Leboy was born in Brooklyn, New York to Samuel LeBoy (originally Lebovitch) and Celia Leboy (née Liborski), both Jewish immigrants. She grew up in Illinois and was the sixth of seven children.
Leboy was a precocious musician, gaining employment as a pianist by age 15, and fame by age 18 with her song "I Wish I Had A Girl". By age 21 she had songs on the Broadway stage in Jumping Jupiter. Notable performers of her day recorded her songs and compositions. Lyrics for many of her songs were written by Gus Kahn whom she married in 1916. They were the parents of Donald Gustave Kahn (July 17, 1918 – April 11, 2008) and Irene Kahn (1922–1985). Grace was played by Doris Day in I'll See You in My Dreams, a film that portrays the lives and times of Leboy and Kahn.