Harry Farjeon (6 May 1878 – 29 December 1948) was a British composer.
Harry Farjeon was born on 6 May 1878 in Hohokus Township, New Jersey, United States, the eldest son of author Benjamin Farjeon, who was from the East End of London, and Margaret, the daughter of American actor Joseph Jefferson. His parents returned to Britain when he was a baby, and he lived in Hampstead in London for the rest of his life. His younger sister, Eleanor Farjeon (b. 1881), with whom he shared a rich imaginary life, wrote children's books and poetry, including the hymn, Morning Has Broken. His younger brothers were J. Jefferson Farjeon (b. 1883), novelist, and Herbert Farjeon (b. 1887), writer of theatrical revues.
Harry studied music privately with Landon Ronald and John Storer, then in 1895 he entered the Royal Academy of Music in London, where he studied composition with Battison Haynes and Frederick Corder, and piano with Septimus Webbe. There he was a contemporary of Arnold Bax, York Bowen, Adam Carse, Eric Coates and Benjamin Dale. An opera, Floretta, to a libretto by his sister, Eleanor, was produced at the Academy in 1899, and two operettas were performed at St George's Hall in 1901 and 1902.
Farjeon left the Royal Academy of Music in 1900, but in 1901 he returned to teach composition. Two years later, at the age of 25, he became the Academy's youngest ever professor, having become the family wage-earner after the death of his father. He also taught at the Blackheath Conservatoire.