The 2020–21 Marshall Thundering Herd men's basketball team represented Marshall University during the 2020–21 NCAA Division I men's basketball season. The Thundering Herd, led by seventh-year head coach Dan D'Antoni, played their home games at the Cam Henderson Center as members of the East Division of Conference USA. They finished the season 15–7, 9–5 in C-USA play to finish in third place in the East Division. They were defeated in the second round of the C-USA tournament by Rice.