Kitson was the son of the Reverend Bernard Meredyth Kitson, a Church of England clergyman, and his wife Helen May Lely. The novelist Anthony Trollope and the painter Sir Peter Lely were among his ancestors.
His three years at King's College, Cambridge, were interrupted in 1945 when he was commissioned into the Royal Engineers and attached to security intelligence Middle East, based in Egypt. He left the army in 1948 and returned to Cambridge.
In 1952, he joined the Slade School of Fine Art at University College, London, as an assistant lecturer in the history of art. He moved on to the Courtauld Institute, London, as a lecturer from 1955 to 1967 and as a reader from 1967 to 1978. He became Professor of the History of Art there in 1978 and was deputy director of the Institute from 1980 to 1985.
Kitson became an international authority on Claude Lorrain and organized the first Lorrain exhibition at the Hayward Gallery, London, in 1969. In 1978 he catalogued the Liber Veritatis, Lorrain's own drawings of his paintings, for the British Museum and later wrote the article on Lorrain for the Macmillan Dictionary of Art (1996).
- J. M. W. Turner (Barnes & Noble, 1963)
- English painting (Art of the Western World) (Golden Press, London, 1964)
- Frans Hals (1965)
- The Age of Baroque: Landmarks of the World's Art, Architecture, Sculpture, Portraits, Landscapes, Interior Decoration (Paul Hamlyn, London, 1966)
- Claude Lorrain, Liber veritatis (British Museum Publications, London, 1978) ISBN 0-7141-0748-4
- The Art of Claude Lorrain (Arts Council, London, 1969)
- The Complete Paintings of Caravaggio (London, Abrams, 1967, new edition Weidenfeld & Nicholson, 1969 and 1986, ISBN 978-0-297-76108-2)
- Rembrandt (Phaidon Press, editions in 1969, 1971, 1978 and 1994)
- Discovering the Italian Baroque by Gabriele Finaldi and Michael Kitson (catalogue of Sir Denis Mahon's collection) (National Gallery, 1997) ISBN 1-85709-177-9
- The Seeing Eye: Critical Writings on Art Michael Kitson (a collection of essays) (Mnemosyne Press, 2008) ISBN 978-0-9525970-1-8
- Complete Bibliography
On 8 July 1950 he married Annabella, the daughter of John Leslie Cloudsley. They had two sons.
In the 1980s Kitson became the partner of Judith Colton 1, an American art scholar.
- Michael William Lely Kitson (1926–1998), art historian by Jason Tomes in Oxford Dictionary of National Biography (Oxford University Press, 2004)
- Obituary in The Independent, 11 August 1998
- Obituary in The Times, 11 August 1998
- Obituary in The Guardian, 11 August 1998
- Obituary in The Daily Telegraph, 12 August 1998
- Memorial address by Neil MacGregor, 23 October 1998