Robert James Hamer (31 March 1911, Kidderminster, Worcestershire – 4 December 1963, London) was a British film director and screenwriter.
Born at 24 Chester Road, Kidderminster, along with his twin Barbara, the son of Owen Dyke Hamer, a bank clerk, and his wife, Annie Grace Brickell. Hamer was educated at Rossall School, an independent school for boys near the town of Fleetwood in Lancashire, and won a scholarship to Corpus Christi College, Cambridge but was sent down (expelled), and began his career in 1934 as a cutting room assistant and from 1935 worked as a film editor involved with such films as Hitchcock's Jamaica Inn (1939) co-produced by Charles Laughton. At the end of the 1930s, he worked on documentaries for the GPO Film Unit.
When his boss at the GPO, Alberto Cavalcanti, moved to Ealing Studios, Hamer was invited to join him there. He gained some experience as a director by substituting for colleagues and contributed the 'haunted mirror' sequence to Dead of Night (1945). He followed this with the three Ealing films under his own name for which he is best remembered: Pink String and Sealing Wax (1946), It Always Rains on Sunday (1947), both featuring Googie Withers, and the black comedy Kind Hearts and Coronets (1949), with Dennis Price and Alec Guinness.