Marcus Eugene Douthit (born April 15, 1980) is an American-Filipino basketball player. He plays for the Hanoi Buffaloes, one of the foreign teams participating at the Thailand Basketball Super League (TBSL). He graduated from Providence College. After his stint with the Providence Friars, he was drafted by the Los Angeles Lakers in the 2004 NBA draft. Born in Syracuse, New York, he became a naturalized Filipino citizen on March 11, 2011, thus allowing him to play for Smart Gilas, the Philippines' men's national basketball team.

Douthit was born in Syracuse, New York to his mother, Melody Douthit. He played high school basketball at Notre Dame Preparatory School, a private, co-educational Roman Catholic high school located in Fitchburg, Massachusetts. The school is primarily known for its basketball program, which has produced notable players such as Michael Beasley, Paul Harris, Lazar Hayward, and Derrick Caracter, to name a few. Before transferring to Notre Dame Prep for his senior year, Douthit played at St. Thomas Aquinas High School in New Britain, Connecticut, the same school that produced Lamar Odom, where he averaged 18 points, 15 rebounds, and four blocks per game.