2003–04 Oklahoma State Cowboys basketball team

The 2003–04 Oklahoma State Cowboys men's basketball team represents Oklahoma State University in the 2003–04 NCAA Division I men's basketball season. The team was led by 14th-year head coach Eddie Sutton. In 2002–03, the Cowboys finished 22–10 (10–6 in the Big 12 Conference).

Four transfers became eligible to play for the Cowboys this season. Joey and Stevie Graham transferred from the University of Central Florida, Daniel Bobik transferred from BYU, and John Lucas III transferred from Baylor University but did not have to sit out the required year after the Baylor University basketball scandal.

The Cowboys won their first four games before traveling to BYU and take on Daniel Bobik's former team and Rafael Araújo, who gave the Cowboys their first setback of the year. After six more consecutive wins, OSU lost in a blowout in their first conference game against Bob Knight's Texas Tech Red Raiders in Lubbock. The Cowboys then won eleven straight conference games before falling in double overtime to the Missouri. Oklahoma State won the regular season conference champtionship finishing with a record of 14-2.

Oklahoma State followed up their regular season Big 12 Conference championship with the tournament championship. OSU received a #2 seed in the East Regional where it defeated the #1 seed St. Joseph's University in the regional final with the game-winning shot coming from John Lucas III. At the Final Four, the Cowboys fell to Georgia Tech on a last-second shot from Will Bynum.