Daniel (Dan) James O'Sullivan (born March 3, 1968, in the Bronx, New York) is a retired American professional basketball player in the NBA.
A 6′10″ (2.08 m), 250 lb (114 kg) center, O'Sullivan attended Fordham University. He played with the Omaha Racers of the Continental Basketball Association,[1] and from the 1990-91 NBA season until 1996, he played with five different NBA teams: Utah Jazz (1990–91), New Jersey Nets (1992–93), Milwaukee Bucks (1992–93), Detroit Pistons (1993–94) and Toronto Raptors (1995–96). He has played for Washington Bullets during the 1993 pre-season (but not in the regular season). He also played with Kinder Bologna, Teamsystem Bologna (1998–99) and Scavolini in the Italian league, and also in Greece for AEK (1999-00).