The 1978 NCAA Division I lacrosse tournament was the eighth annual tournament hosted by the National Collegiate Athletic Association to determine the team champion of men's college lacrosse among its Division I programs at the end of the 1978 NCAA Division I lacrosse season.

Johns Hopkins defeated Cornell in the championship game, 13–8, using a three-goal performance by midfielder Bob DeSimone.

Twelve NCAA Division I college men's lacrosse teams met after having played their way through a regular season, and for some, a conference tournament.

The finals was a showdown of the #1 and #2 ranked teams, with Johns Hopkins lone loss coming on April 15 to Cornell (16–11) at Homewood Field in Baltimore.

Mike O'Neill, attackman from Johns Hopkins, was later named the Division 1 National Player of the Year and was named the tournament outstanding player, finishing with one goal and three assists in the finals.