Trapnell is a surname. Notable people with the surname include:
Anna Trapnell, alleged Prophetess in England in the 1650s Barry Trapnell (1924–2012), English first-class cricketer Coles Trapnell (1910–1999), American television producer, writer, and director Frederick M. Trapnell (1902–1975), United States Navy admiral and aviation pioneer Garrett Brock Trapnell (1938–1993), con man, bank robber, and aircraft hijacker of the 1960s and early 1970s Thomas J. H. Trapnell (1902–2002), United States Army general