Le Brun studied painting at the Slade School of Art (1970–74) and Chelsea School of Art (1974–75). Since then he has taught and lectured extensively at art schools throughout the country, in particular until 1984 at Brighton, The Slade, Chelsea, and Wimbledon. In 1982 he participated in the influential "Zeitgeist" exhibition at the Martin-Gropius-Bau Berlin. Following this he had many solo exhibitions in galleries both in Europe and the United States, such as Sperone Westwater, Rudolf Zwirner, Nigel Greenwood, LA Louver and Marlborough Fine Art. Le Brun has exhibited in many significant surveys of international art, including "Nuova Immagine", Milan 1981, "An International Survey of Recent Painting and Sculpture", MoMA New York 1984, "Avant-garde in the Eighties", Los Angeles 1987 and "Contemporary Voices", MoMA New York 2005.
He is also a printmaker, for which he was elected to the Royal Academy in 1996 (category engraver), coincidentally the year in which he made his first sculpture. He was one of the five artists shortlisted for the Angel of the South monumental sculpture project in 2008. In 2011 he was the chief co-ordinator of the Royal Academy Summer Exhibition. On 8 December 2011 he was elected President of the Royal Academy and interviewed about his role by the Guardian Professional Networks in 2013. He lives and works in London and is married to the artist Charlotte Verity.
The late Bryan Robertson, former director of the Whitechapel Gallery, described Le Brun for the exhibition "Christopher Le Brun Paintings 1991–1994" at Marlborough Fine Art, London, as follows:
"On consistent terms which Le Brun has made uniquely his own, he has created a considerable body of work in large or quite small paintings, with drawings and many engravings of inventive refinement which, put all together, makes a visible and credible world of its own. An intensity of visual concept in its broad sense sustains an oddly relaxed, divergent and exploratory tension derived from the calculated and extremely variable deployment of each brushmark in its placement on the canvas. He offers us a feast for the eye demanded by Delacroix as the first requisite of any painting before it has meaning. Some of the ways in which Le Brun deploys pigment appear to stem from early Guston and, before that, from the late Monet that we encounter in the Musee Marmotton – but the world celebrated by Le Brun in this use of paint stems in essence from the romantic past of poetry, myth and legend."