2003 NCAA Division III men's basketball tournament

The 2003 NCAA Division III men's basketball tournament was the 29th annual single-elimination tournament to determine the national champions of National Collegiate Athletic Association (NCAA) men's Division III collegiate basketball in the United States.

The field contained forty-eight teams, and each program was allocated to one of four sectionals. All sectional games were played on campus sites, while the national semifinals, third-place final, and championship finals were contested at the Salem Civic Center in Salem, Virginia.

Williams defeated Gustavus Adolphus, 67–65, in the championship, clinching their first national title.

The Ephs (31–1) were coached by Dave Paulsen. Paulsen would later coach at Division I programs Bucknell and George Mason.

Benjamin Coffin, also from Williams, was named Most Outstanding Player.

National finals

 * Site: Salem Civic Center, Salem, Virginia