Richmond captured the NBA Rookie of the Year Award in the 1988–89 season, after averaging 22 points per game for the Warriors. He was a key part of Don Nelson's fast-paced offense, which was dubbed "Run TMC" after the first names of its three main components, Tim Hardaway, Mitch Richmond and Chris Mullin, respectively. The trio were named after the influential rap group Run DMC. In addition to the shooting he provided, he complemented Hardaway's passing and fast break skills and Mullin's shooting skills by slashing to the hoop as part of the Warriors' attack.
After three years of scoring 22+ points a game in Golden State, Richmond, on November 1, 1991, was traded (along with Les Jepsen) to the Sacramento Kings during the 1991–92 season in exchange for the rights to Billy Owens, and became arguably the team's first star since the franchise moved to Sacramento in 1985. Staying with the Kings until 1998, Richmond was the team's leading scorer in each of his 7 seasons there, averaging no fewer than 21.9 a game each season. Between 1993 and 1998, Richmond was a fixture on the Western Conference's All-Star team, and he won MVP honors at the All-Star Game in Phoenix, in 1995. In the middle of his prime, Richmond was selected to the United States' Olympic team (Dream Team III), earning a gold medal in Atlanta. During his prime, Richmond was recognized as one of basketball's all time best pure shooters.
Richmond was traded by the Kings, along with Otis Thorpe, to the Washington Wizards for Chris Webber in May 1998, a move that keyed the Kings' transformation from perennial doormat to an elite title contender. However, things did not work out as well for Richmond. In three years with the Wizards, he lost a lot of the shooting touch he displayed as a King, and his days as a regular were numbered after missing half of the 2000–01 season.
Richmond signed as a free agent with the Los Angeles Lakers, where he played the final year of his career. Playing strictly off the bench, he averaged 4 points a game. He earned an NBA championship ring with the Lakers in 2002 but played sparingly in the postseason, logging 4 minutes overall. In game 4 of the finals, Richmond dribbled out the clock to win the title with the Lakers.