Percy MacKaye (1875–1956) was an American dramatist and poet.
MacKaye was born in New York City, New York. After graduating from Harvard in 1897, he traveled in Europe for three years, residing in Rome, Switzerland and London, studying at the University of Leipzig in 1899–1900. He returned to New York City to teach at a private school until 1904, when he joined a colony of artists and writers in Cornish, New Hampshire, and devoted himself entirely to dramatic work.
He wrote the plays The Canterbury Pilgrims in 1903, Sappho and Phaon in 1907, Jeanne D'Arc in 1907, The Scarecrow in 1908, Anti-Matrimony in 1910, and the poetry collection The Far Familiar in 1937. In 1950, MacKaye published The Mystery of Hamlet King of Denmark, or What We Will, a series of four plays written as prequels to William Shakespeare's Hamlet.
He was made a member of the National Institute of Arts and Letters in 1914. In the 1920s, MacKaye was poet in residence at Miami University in Oxford, Ohio. He lectured on the theatre at Harvard, Yale, Columbia and other universities in the United States. He was the son of actor, impresario and theatrical technology innovator Steele MacKaye, and brother of philosopher James MacKaye and conservationist Benton MacKaye.