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. 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.