James Hyman received his doctorate from the Courtauld Institute in London, where he subsequently taught. He worked for the Saatchi Collection, Christies and Helly Nahmad Gallery before opening his own gallery.

An art historian and art dealer, his book, The Battle for Realism. Figurative Art in the Cold War (Yale University Press, 2001) was shortlisted for the W. B. Berger Prize for studies in British Art History.

His monograph Derrick Greaves. From Kitchen Sink to Shangri La was published by Lund Humphries in 2007.

James is presently preparing a catalogue raisonne on the paintings of Michael Andrews. Other essay subjects include Francis Bacon, Tony Bevan, Henri Cartier Bresson, Lucian Freud, Philip Guston, Anselm Kiefer and Leon Kossoff.

A collector of photographs from the 1840s to the present, a selection from his collection of twentieth century Modernist works was the subject of a single-owner evening sale at Christies, New York in 2007.

He is a former Treasurer of the International Association of Art Critics (AICA, British Section), is on the Executive of the Society of London Art Dealers (SLAD), and on the Executive Board of the Association of International Photography Dealers (AIPAD).

He opened his first gallery in Mason's Yard, St. James's in 2002 before moving to a large purpose-designed gallery in Savile Row, Mayfair in Summer 2007.