Hyman was born in Hove, Sussex in 1946. He attended the Slade School of Fine Art between 1963-67. He began to publish articles on painting in the London Magazine in the late 1970s, and was a contributing editor to Artscribe. In 1979 he curated the controversial exhibition Narrative Paintings at the ICA in London and the Arnolfini in Bristol. In 1980 and 1982 he was a Visiting Professor in Baroda, (Vadodara) India, and completed several extensive British Council lecture tours.
Hyman is a recognised authority on the work of many artists including Pierre Bonnard and the painters of the Sienese School as well as more contemporary artists, such as Howard Hodgkin R.B. Kitaj and the Indian painter Bhupen Khakhar Since 1990 he has been a regular contributor to the Times Literary Supplement and has written on a variety of subjects including: Ernst Ludwig Kirchner Henry Darger and German Romanticism . Hyman has also written extensively on film, including articles on Fellini , Andrei Tarkovsky and Derek Jarman In 1998 his monograph on Bonnard was published by Thames and Hudson, and, in the same year, his book on Bhupen Khakhar was published in India.
Hyman and Roger Malbert curated the Hayward Gallery touring exhibition Carnivalesque in 2000.
In 2001, along with cultural historian Patrick Wright, Hyman organised the acclaimed Stanley Spencer retrospective at Tate Britain. He also co-curated the major exhibition British Vision at the Museum of Fine Arts, Ghent in 2007-08.
Hyman is also well known for his lectures that investigate the tangents and marginalia of art history. He has been a visiting lecturer in art at both the Slade School of Fine Art, Glasgow School of Art, Central St. Martins and The Royal College of Art for many years as well as lecturing on art history at The Working Men's College, The Tate, the National Gallery, London and MOMA in New York.