After playing college basketball for the LSU Tigers, O'Neal was drafted by the Orlando Magic with the first overall pick in the 1992 NBA draft. He quickly became one of the best centers in the league, winning Rookie of the Year in 1992–93 and leading his team to the 1995 NBA Finals. After four years with the Magic, O'Neal signed as a free agent with the Los Angeles Lakers. They won three consecutive championships in 2000, 2001, and 2002. Amid a feud between O'Neal and his teammate Kobe Bryant, O'Neal was traded to the Miami Heat in 2004, and his fourth NBA championship followed in 2006. Midway through the 2007–2008 season he was traded to the Phoenix Suns. After a season-and-a-half with the Suns, O'Neal was traded to the Cleveland Cavaliers in the 2009–10 season. O'Neal played for the Boston Celtics in the 2010–11 season before retiring.

O'Neal's individual accolades include the 1999–2000 Most Valuable Player (MVP) Award; the 1992–93 NBA Rookie of the Year award; 15 All-Star Game selections, three All-Star Game MVP awards; three Finals MVP awards; two scoring titles; 14 All-NBA team selections, and three NBA All-Defensive Team selections. He is one of only three players to win NBA MVP, All-Star Game MVP and Finals MVP awards in the same year (2000); the other players are Willis Reed in 1970 and Michael Jordan in 1996 and 1998. He ranks 8th all-time in points scored, 6th in field goals, 15th in rebounds, and 8th in blocks. O'Neal was honored as one of the league's greatest players of all-time by being named to the NBA 50th Anniversary Team in 1996. Due to his ability to dunk the basketball and score from close range, O'Neal also ranks third all-time in field goal percentage (58.2%) and led the league in field goal percentage ten times. O'Neal was elected into the Naismith Memorial Basketball Hall of Fame in 2016.  He was elected to the FIBA Hall of Fame in 2017. In October 2021, O'Neal was again honored as one of the league's greatest players of all-time by being named to the NBA 75th Anniversary Team.