The Harcourt Additional Papers consist of:
- Papers of Sir William Harcourt, 1805-1929, including correspondence, printed material, speeches, commonplace books, newscuttings, and photographs
- Family papers of Lewis Harcourt, 1871-1922
- Correspondence and papers of Mary Harcourt, 1776-1950
- Correspondence of Edward Harcourt, 1842-91