William Catesby (1450 – 25 August 1485) was one of Richard III of England's principal councillors. He also served as Chancellor of the Exchequer and Speaker of the House of Commons during Richard's reign. In July 1484, William Collingbourne, a Tudor agent, tacked up a lampooning poem to St. Paul's Cathedral, which mentions Catesby among the three aides to King Richard, whose emblem was a white boar: The Catte, the Ratte and Lovell our dogge rulyth all Englande under a hogge.