Boston Celtics All-Stars
18 players
18 players were All-Stars in a season with the Boston Celtics. John Havlicek did it the most, 13 times (1966–1978). On a roster now: Jayson Tatum, Jaylen Brown, Kyrie Irving, and Al Horford.
Selections from Wikipedia's list of NBA All-Stars; a player counts for each club he played for that season. Seasons are on file in full from 1993-94; before that only some of the stars are, so an older name can be missing.