The 2004–05 George Washington Colonials men's basketball team represented George Washington University in the 2004–05 NCAA Division I men's basketball season. The Colonials, led by head coach Karl Hobbs, played their home games at the Charles E. Smith Center in Washington, D.C., as members of the Atlantic 10 Conference.
The Colonials finished the regular season at 11–5 in conference play, registering a 19–7 overall record going into the postseason. They defeated Fordham, Temple, and Saint Joseph's to win the Atlantic 10 tournament and secure the conference's automatic bid to the NCAA tournament. Playing as the 12 seed in the West region, George Washington lost to No. 5 seed Georgia Tech, 80–68.