British actor, founder (with his wife, actress Josephine Wilson) of the Mermaid Theatre, the first new theatre to open in the City of London since the 17th century.

Miles studied at Pembroke College, Oxford, and taught briefly before quitting to pursue an acting career. He made his professional debut in 1930, married Josephine Wilson in 1931, and spent several years in repertory as actor, designer, stage manager, and general factotum. He became a respected character actor in such stage roles as Christopher Sly in The Taming of the Shrew and Iago in Othello and in such film roles as a rough seaman in In Which We Serve (1942), the kindly, simple Joe Gargery in Great Expectations (1946), and a murderous kidnapper in The Man Who Knew Too Much (1956).

In 1950 Miles founded the first Mermaid Theatre as a small Elizabethan-style playhouse behind his home. He established the Mermaid Theatre Trust to raise money for a permanent venue, and in 1959 the 500-seat Mermaid Theatre officially opened. The Mermaid achieved moderate artistic success with an extraordinary variety of plays, ranging from Greek tragedies to modern musicals, but it had ongoing financial problems. These difficulties increased in the late 1970s, when Miles embarked on an extensive reconstruction of the Mermaid, and a few years later the trustees ordered the theatre's sale.

Miles was knighted in 1969 and made a life peer in 1979.