Ian Ambury Miller Prior ONZM (16 October 1923 – 17 February 2009) was a New Zealand doctor, epidemiologist, environmental campaigner and arts patron. He is acknowledged as the founder of epidemiology in New Zealand. He conducted pioneering epidemiological studies of Māori, Cook Islanders and Tokelau Islanders in the 1960s. He was active in a number of environmental campaigns including the International Physicians for the Prevention of Nuclear War, and was well known for his support of the arts, in particular the Wellington Sculpture Trust.