They Walk Alone is a 1938 thriller play by the British writer Max Catto.

[1] After premiering at the Q Theatre in Kew Bridge, it transferred to London's West End where it ran for 156 performances between 19 January and 3 June 1939 initially at the Shaftesbury Theatre before switching to the Comedy Theatre.

The cast included Beckett Bould, Jimmy Hanley, Rene Ray, Carol Goodner and Beatrix Lehmann.

[2] It also ran for 21 performances at the Shubert Theatre on Broadway in 1941.

[3] In 1948 it was adapted into the film Daughter of Darkness directed by Lance Comfort and starring Anne Crawford, Maxwell Reed and Siobhán McKenna.