The 2003–04 BYU Cougars men's basketball team represented Brigham Young University as a member of the Mountain West Conference during the 2003–04 season.

Led by head coach Steve Cleveland, the Cougars finished second in the Mountain West Conference regular season standings.

The team received an at-large bid to the NCAA tournament – their third bid in four years under Cleveland.

BYU finished the season with a 21–9 record (10–4 MWC).

Roster [3] [4]