The 2018 NCAA Division I Men's Lacrosse Championship weekend was the 48th annual single-elimination tournament to determine the national championship for National Collegiate Athletic Association (NCAA) Division I men's college lacrosse. Seventeen teams competed in the tournament, based upon their performance during the regular season. For nine teams, entry into the tournament was by means of a conference tournament automatic qualifier and/or play in, while for eight teams at-large selection was determined by the NCAA selection committee.