Frederick Theodore Albert Delius CH (born Fritz Theodor Albert Delius; /ˈdiːliəs/; 29 January 1862 – 10 June 1934) was an English composer. Born in Bradford in the north of England to a prosperous mercantile family, he resisted attempts to recruit him to commerce.

In the early years of the 20th century, Delius composed some of his most popular works, including Brigg Fair (1907), In a Summer Garden(1908, revised 1911), Summer Night on the River (1911), and On Hearing the First Cuckoo in Spring (1912), of which McVeagh comments, "These exquisite idylls, for all their composer's German descent and French domicile, spell 'England' for most listeners.