The Unpleasantness at the Bellona Club is a 1928 mystery novel by Dorothy L. Sayers, her fourth featuring Lord Peter Wimsey. Much of the novel is set in the Bellona Club, a fictional London club for war veterans (Bellona being a Roman goddess of war).

Dorothy Leigh Sayers (13 June 1893 - 17 December 1957) was an English crime novelist, playwright, translator and critic.