1998–99 Boston Celtics season

The 1998–99 NBA season was the 53rd season for the Boston Celtics in the National Basketball Association. Due to a lockout, the regular season began on February 5, 1999, and was cut from 82 games to 50.

This season is memorable as the Celtics received the tenth overall pick in the 1998 NBA draft, and selected small forward Paul Pierce from the University of Kansas. During the off-season, the team acquired second-year center Tony Battie from the Los Angeles Lakers. Pierce would get off to a fast start as he was named Rookie of the Month in February. However, after a 7–7 start to the regular season, the Celtics struggled losing ten of their next eleven games. At mid-season, the team traded Andrew DeClercq to the Cleveland Cavaliers in exchange for Vitaly Potapenko. Celtics fans began to get restless with head coach Rick Pitino's slow growth, as the team finished in fifth place in the Atlantic Division with a 19–31 record.

Antoine Walker averaged 18.7 points, 8.5 rebounds and 1.5 steals per game, while second-year star Ron Mercer averaged 17.0 points and 1.6 steals per game, and Pierce provided the team with 16.5 points, 6.4 rebounds and 1.7 steals per game, and was named to the NBA All-Rookie First Team, and finished in third place in Rookie of the Year voting. In addition, Kenny Anderson contributed 12.1 points and 5.7 assists per game, while off the bench, sixth man Dana Barros provided with 9.3 points and 4.2 assists per game, and Battie averaged 6.7 points, 6.0 rebounds and 1.4 blocks per game.

Following the season, Mercer was traded along with Popeye Jones to the Denver Nuggets, and Bruce Bowen signed as a free agent with the Philadelphia 76ers.