The 1998–99 George Mason Patriots Men's basketball team represented George Mason University during the 1998–99 NCAA Division I men's basketball season.
This was the 33rd season for the program, the second under head coach Jim Larrañaga.
The Patriots played their home games at the Patriot Center in Fairfax, Virginia.
Colonial Athletic Association Player of the Year Colonial Athletic Association All-Conference Team Colonial Athletic Association Defensive Player of the Year Colonial Athletic Association Coach of the Year