Arnold Leonard Epstein, known as Bill Epstein (13 September 1924, Liverpool – 9 November 1999, Hove), was a British social anthropologist. A member of the "Manchester School", he was known for his research on ethnicity and identity, particularly his book Ethos and Identity (1978), and for his ethnographic work in Central Africa and New Britain. He was a professor at the Australian National University (1958–1972) and Sussex University (1972–1982), as well as the vice president of the Royal Anthropological Institute (1982–1984).