Sargy Mann was born Martin Oliver Henson Mann in Hythe, Kent, England on 29 May 1937. He was educated at Dartington School in Devon (1943–53), where he acquired his lifelong nickname 'Sargy', and Oxford Technical College (1953–58), before training at Camberwell College of Arts and Crafts (1960–64), where his tutors included Frank Auerbach, Euan Uglow and Dick Lee; he also recalled drawing ‘kind of unofficially’ in the life room at St. Martin’s where Leon Kossoff was teaching in the late 1960s. In 1967 he returned to Camberwell as a postgraduate student, and then as a part-time teacher (1969–88), also teaching at the Camden Arts Centre throughout the same period. He was deeply influenced by the post-Impressionists and his work celebrated light and colour. In 1973 he had his first solo exhibition at the Salisbury Festival of Arts, the year he had a cataract operation, followed by his first retinal detachment, resulting in blindness in one eye in 1978; a second, in 1980, leaving only partial vision in one eye; and total blindness from 2005, although he continued to paint for the rest of his life, finding new ways of working. In 1976 he married fellow artist Frances Carey, living first in Peckham, south London (1980–90), and then moving to Bungay in Suffolk, where he remained for the rest of his life.
Mann held his first solo exhibition at Cadogan Contemporary in 1987, followed by a further 14 exhibitions, as well as participating in numerous mixed exhibitions from 1964 onwards at galleries including Roland, Browse & Delbanco, the Whitechapel Art Gallery and the South London Gallery. In 1994 he curated the exhibition Bonnard at Le Bosquet at the Hayward Gallery and between 1999–08 was also Visiting Lecturer at the Prince’s Drawing School. Sargy Mann died in Suffolk, England on 5 April 2015 and two further posthumous exhibition of his last works were held at Cadogan Contemporary (2015 and 2016), followed by an exhibition of his late paintings, curated by Chantal Joffe, at the Royal Drawings School in 2019 and a retrospective at the Attenborough Gallery, Leicester, the same year.