Gregory Pratt, M.D. is a fictional character from the medical drama series ER, portrayed by Mekhi Phifer. He first appears as a recurring character towards the end of the eight season, becoming a main character from the start of the ninth season until the start of the fifteenth season.

ER is an American medical drama television series created by Michael Crichton that aired on NBC from September 19, 1994, to April 2, 2009, with a total of 331 episodes spanning 15 seasons. It was produced by Constant c Productions and Amblin Television, in association with Warner Bros. Television. ER follows the inner life of the emergency room (ER) of Cook County General Hospital in Chicago, and various critical issues faced by the department's physicians and staff.