The 1984 NCAA Division I baseball tournament was played at the end of the 1984 NCAA Division I baseball season to determine the national champion of college baseball. The tournament concluded with eight teams competing in the College World Series, a double-elimination tournament in its thirty eighth year. Eight regional competitions were held to determine the participants in the final event. Six regions held a four team, double-elimination tournament while two regions included six teams, resulting in 36 teams participating in the tournament at the conclusion of their regular season, and in some cases, after a conference tournament.^[1] The thirty-eighth tournament's champion was Cal State Fullerton, coached by Augie Garrido. The Most Outstanding Player was John Fishel of Cal State Fullerton.

Bold indicates CWS participant.

• Arizona State
• Cal State Fullerton
• North Carolina
• Oklahoma State
• Texas

The opening rounds of the tournament were played across eight regional sites across the country, six consisting of four teams and two of six teams.^[2] The winners of each Regional advanced to the College World Series.

Bold indicates winner.

• 1984 NCAA Division I softball tournament
• 1984 NCAA Division II baseball tournament
• 1984 NCAA Division III baseball tournament
• 1984 NAIA World Series