Sydney Box (29 April 1907 – 25 May 1983) was a British film producer and screenwriter, and brother of British film producer Betty Box. In 1940, he founded the documentary film company Verity Films with Jay Lewis.He produced and co-wrote the screenplay, with his then wife Muriel Box, for The Seventh Veil (1945), which received the 1946 Oscar for best original screenplay. The couple were then hired by the Rank Organisation to run Gainsborough Studios.