Alexandre-Pierre Georges Guitry (French: [gitʁi]; 21 February 1885 – 24 July 1957), known as Sacha Guitry, was a French stage actor, film actor, director, screenwriter, and playwright of the boulevard theatre. He was the son of a leading French actor, Lucien Guitry, and followed his father into the theatrical profession. He became known for his stage performances, particularly in boulevardier roles. He was also a prolific playwright, writing 115 plays throughout his career. He was married five times, always to rising actresses whose careers he furthered. Probably his best-known wife was Yvonne Printemps to whom he was married between 1919 and 1932.

Guitry's plays range from historical dramas to contemporary light comedies. Some have musical scores, by composers including André Messager and Reynaldo Hahn. When silent films became popular Guitry avoided them, finding the lack of spoken dialogue fatal to dramatic impact. From the 1930s to the end of his life he enthusiastically embraced the cinema, making as many as five films in a single year.

The later years of Guitry's career were overshadowed by accusations of collaborating with the occupying Germans after the capitulation of France in the Second World War. The charges were dismissed, but Guitry, a strongly patriotic man, was disillusioned by the vilification he received from some of his compatriots. By the time of his death, his popular esteem had been restored to the extent that 12,000 people filed past his coffin before his burial in Paris.