Thomas Clarkson, 1760–1846, English abolitionist. He devoted most of his life to agitation against slavery, and the voluminous information that he gathered on the slave trade helped to influence Parliament. With William Wilberforce he shares the chief credit for the act of 1807 abolishing the British slave trade. His best-known books are a history of Parliament's abolition of the slave trade (1805) and a memoir of William Penn (1813).
See his correspondence with H. Christophe, ed. by E. L. Griggs and C. H. Prator (1952, repr. 1968).