Scott grew up in Inglewood, California, and played at Morningside High School, in the shadow of what was then the Lakers' home arena, The Forum.

Selected by the San Diego Clippers in the first round, with the fourth pick of the 1983 NBA draft, Scott was traded to the Los Angeles Lakers in 1983 in exchange for Norm Nixon.

Scott was a key player for the Lakers during the Showtime era, being a starter alongside Magic Johnson, James Worthy, Kareem Abdul-Jabbar and A.C. Green.

In 1987–88, Scott enjoyed his best season, leading the NBA champion Lakers in scoring, averaging a career-best 21.7 ppg, and in steals (1.91 spg).

In Game 1 of the Pacers' first-round playoff matchup against the Orlando Magic, Scott hit the game-winning three-point shot with 2.4 seconds left.

Scott was left unprotected by the Pacers in the 1995 NBA expansion draft and was selected by the Vancouver Grizzlies, where he played one season.

[5] After one season with the Greek Basket League champions, Scott retired from playing professional basketball, and began his coaching career.

[6] On June 27, 2000, Scott was hired to coach the New Jersey Nets after being offered the job the previous day by general manager Rod Thorn.

Scott was considered for the Indiana Pacers job prior to reaching with Thorn, who himself had been hired recently to try and turn over a team that had missed the playoffs in five of the past six seasons while having had twelve head coaches in 23 seasons as an NBA franchise; the day that Scott was hired was right before the 2000 NBA draft, for which the Nets had the first overall pick.

[8] However, the team would improve in dividends in the 2001–02 season with the arrival of Jason Kidd in a trade that sent Stephon Marbury to the Phoenix Suns.

In the first round against the Indiana Pacers, the Nets had to play the full five games to narrowly avoid an upset, which saw them go on a 13-2 barrage in the second overtime to win their first playoff series since 1984.

In Game 1, Kidd had the first triple-double in an NBA Finals since 1993, but the Lakers led by a score of 42–19 only six minutes into the second quarter and never looked back in a 99–94 win.

They were 34–15 at the All-Star break, but they played below .500 the rest of the year to wind up with 49 wins, which was one short of the Detroit Pistons for the number one seed in the East.

They were matched in the NBA Finals to face the 60-win San Antonio Spurs, headlined by two-time league MVP Tim Duncan, a retiring David Robinson, and future stars Manu Ginobili and Tony Parker.

However, the Nets went cold in an instant, losing the lead through the help of Duncan and newly acquired Stephen Jackson to score ten points in the span of two minutes.

[16] By July 2003, tension was apparent with the Nets, who were being dogged by reports that Kidd asked that Scott to be fired in order for him to agree to re-sign to a six-year contract.

Scott himself admitted that his stubborn qualities with Kidd requires him to need to try to be more of a "taskmaster" in being more hands on, particularly with the departure of assistant coach Eddie Jordan, who had left for the Washington Wizards after having done his share of calling plays.

Scott was approaching the 2003–04 season as the last one of his contract while being dogged by articles that had anonymous sources criticizing his coaching in the 2003 NBA Finals.

[17] Scott was fired during the 2003–04 season, as New Jersey had a disappointing 22–20 record coming into the All-Star break, even though they were leading their division at the time of his dismissal.

On July 1, 2010, Scott was named head coach of the Cleveland Cavaliers, a few days before the team lost star LeBron James to the Miami Heat.

Scott was reunited with Baron Davis (whom he coached with the Hornets) when a mid-season trade brought Davis to Cleveland, and helped the Cavaliers close the season with several victories,[28] including a 102–90 upset victory over LeBron James and the Miami Heat,[29] which ensured that Cleveland did not have the worst record in the league at the season's end.

[30] Cleveland used their first overall pick to draft Kyrie Irving, who became the second point guard Scott coached to the Rookie of the Year award.

[31][32] Though the Cavaliers ranked in the bottom five of the league in defensive efficiency in each of his three seasons,[33] analysts were surprised at the firing given the team's young and oft-injured rosters.

[43] In June 2013, Scott and Anita separated and in March 2014, he filed for divorce after 29 years of marriage due to irreconcilable differences.

[44] On July 11, 2020, Scott married Cece Gutierrez, a registered nurse and cast member of VH1's reality show Basketball Wives.