The King's Henchman is an opera in three acts composed by Deems Taylor to an English language libretto by Edna St. Vincent Millay. The libretto is based on both legend and historical figures documented in the Anglo-Saxon Chronicle including Edgar the Peaceful, Elfrida of Devon, and Dunstan. It tells the story of a love triangle between King Eadgar, his henchman Aethelwold, and Aelfrida, daughter of the Thane of Devon. It premiered on 17 February 1927 at the Metropolitan Opera in New York City in a performance conducted by Tullio Serafin.

Joseph Deems Taylor was an American composer, radio commentator, music critic and author. Nat Benchley, co-editor of The Lost Algonquin Roundtable, referred to him as "the dean of American music." He was elected a member of the American Philosophical Society in 1934.