The 2005 NCAA Division I men's ice hockey tournament involved 16 schools playing in single-elimination play to determine the national champion of men's NCAA Division I college ice hockey. It began on March 25, 2005, and ended with the championship game on April 9. A total of 15 games were played.
This tournament marked the first time in NCAA history, in any Division, in any sport, male or female, that the 4 semi-finalists all hailed from the same conference. Denver, Colorado College, Minnesota, and North Dakota were all members of the Western Collegiate Hockey Association (WCHA).
The NCAA Men's Division I Ice Hockey Championship is a single-elimination tournament featuring 16 teams representing all six Division I conferences in the nation. The Championship Committee seeds the entire field from 1 to 16 within four regionals of 4 teams. The winners of the six Division I conference championships receive automatic bids to participate in the NCAA Championship. Regional placements are based primarily on the home location of the top seed in each bracket with an attempt made to put the top-ranked teams close to their home site.
The at-large bids and seeding for each team in the tournament was announced on March 20, 2005. The Western Collegiate Hockey Association (WCHA) had five teams receive a berth in the tournament, Hockey East had four teams receive a berth in the tournament, the ECACHL had three teams receive a berth in the tournament, the Central Collegiate Hockey Association (CCHA) had two teams receive a berth in the tournament, while Atlantic Hockey and College Hockey America (CHA) both received a single bid for their tournament champions.
<small>Number in parentheses denotes overall seed in the tournament.</small>
<small>Note: * denotes overtime period(s)</small>
<nowiki>*</nowiki> Most Outstanding Player(s)