A popular English surname, Pratt is also found in Ireland and Belgium. The Old English term ‘praett’ means a cunning trick or trickster. So the surname of Pratt came to mean a practical joker or someone who dresses or acts wildly or foolishly. Spelling variations for Pratt include Prat and Pratte. Pratt families in England are originally settled in the Norfolk county. Many Pratt families reside in the southeastern portion of Ireland. In the United States the Pratt surname is in Massachusetts, New York, California, New Jersey, Ohio, Michigan, Missouri, Iowa and Washington. Famous: William Henry Pratt (the birth name of actor, Boris Karloff), Todd Alan Pratt (a professional baseball player), Nolan Pratt (a professional hockey player of Canada), Dudley Pratt (sculptor), Spencer Pratt (television personality), Charles Pratt (founder of the Pratt Institute), Francis A. Pratt (engineer and developer of Pratt & Whitney Aircraft Engines) and Caleb & Thomas Pratt (inventors of the Pratt truss bridge design).