The 2018 NCAA Division III men's basketball tournament was the 44th annual single-elimination tournament to determine the national champion of men's NCAA Division III college basketball in the United States.

Nebraska Wesleyan defeated Wisconsin–Oshkosh in the final, 78–72, to win their first national title.

The following 43 teams were automatic qualifiers for the 2018 NCAA field by virtue of winning their conference's automatic bid (except for the UAA, whose regular-season champion received the automatic bid).

[1] The following 21 teams were awarded qualification for the 2018 NCAA field by the NCAA Division III Men's Basketball Committee.

[1] The committee evaluated teams on the basis of their win-loss percentage, strength of schedule, head-to-head results, results against common opponents, and results against teams included in the NCAA's final regional rankings.