The Courtauld Institute of Art was founded in 1931 with a gift of French Impressionist (Impressionism) and Postimpressionist (Post-Impressionism) paintings by the wealthy silk manufacturer Samuel Courtauld (1876–1947), but the collection was not made available to the public until 1958, when a gallery was opened in Woburn Square, Bloomsbury. In 1990 the collection was transferred to Somerset House (built 1770s–90s), which was designed by Sir William Chambers (Chambers, Sir William) originally as government offices.

Throughout the 20th century there were other major gifts to the institute in addition to that by Courtauld. The collections of Viscount Lee of Fareham and of Mark Gambier-Perry both contributed works by Old Masters, the latter bequest in particular containing many early Italian paintings. The Princess Gate Collection, bequeathed in 1978 by Count Antoine Seilern, further strengthened the Old Masters collection and is particularly rich in works by Peter Paul Rubens (Rubens, Peter Paul) and Giovanni Battista Tiepolo (Tiepolo, Giovanni Battista). The collection of Sir Robert Witt includes some 3,500 drawings; it is particularly strong in British and Italian works as well as being representative of the Dutch, Flemish, and French schools. Of considerable importance as a research tool is the Witt Library of photographs and reproductions of pictures and drawings, which comprises almost two million items. In 1967 the galleries acquired a number of English watercolours from the bequest of William Spooner. One of the Courtauld Institute's earliest bequests, that of the art critic Roger Eliot Fry (Fry, Roger), contributed 20th-century British paintings and drawings as well as pottery and furniture.