The 2025–26 Marshall Thundering Herd men's basketball team represented Marshall University during the 2025–26 NCAA Division I men's basketball season. The Thundering Herd, led by second-year head coach Cornelius Jackson, played their home games at the Cam Henderson Center as members of the Sun Belt Conference. They finished the season 19–13, 11–7 in Sun Belt play to finish in a tie for second place. As the No. 2 seed in the Sun Belt tournament, they lost to Georgia Southern in the semifinals.