The 1998–99 NBA season was the 31st season for the Phoenix Suns in the National Basketball Association.^[1] On March 23, 1998, the owners of all 29 NBA teams voted 27–2 to reopen the league's collective bargaining agreement, seeking changes to the league's salary cap system, and a ceiling on individual player salaries. The National Basketball Players Association (NBPA) opposed to the owners' plan, and wanted raises for players who earned the league's minimum salary. After both sides failed to reach an agreement, the owners called for a lockout, which began on July 1, 1998, putting a hold on all team trades, free agent signings and training camp workouts, and cancelling many NBA regular season and preseason games.^{[2][3][4][5][6]} Due to the lockout, the NBA All-Star Game, which was scheduled to be played in Philadelphia, Pennsylvania on February 14, 1999, was also cancelled.^{[7][8][9][10][11]} However, on January 6, 1999, NBA commissioner David Stern, and NBPA director Billy Hunter finally reached an agreement to end the lockout. The deal was approved by both the players and owners, and was signed on January 20, ending the lockout after 204 days. The regular season began on February 5, and was cut short to just 50 games per team instead of the regular 82-game schedule.^{[12][13][14][15][16]}

During the off-season, the Suns signed free agent Tom Gugliotta,^{[17][18][19][20]} acquired Luc Longley from the Chicago Bulls,^[21][22][23] acquired rookie forward Pat Garrity from the Dallas Mavericks,^[24][25][26] signed Chris Morris, and re-signed former Suns center Joe Kleine.^[27] Head coach Danny Ainge returned for his third season with the team. After a 15–18 start, the Suns won 12 of their final 17 games, and finished tied with the Sacramento Kings for third in the Pacific Division with a record of 27–23.^[28] All home games were played in America West Arena.

Starting point guard Jason Kidd finished the regular season leading the league with 10.8 assists per game, plus contributing 2.3 steals per game. Four Suns would average double-digits in points per game, with Gugliotta leading the team with 17.0 points and 8.9 rebounds, plus contributing 1.4 steals per game, while Kidd averaged 16.9 points per game, Clifford Robinson provided with 16.4 points and 1.5 steals per game, and Rex Chapman contributed 12.1 points per game.^[29] Kidd also led the league in total minutes played and was third in total steals, before being selected to both the All-NBA and All-Defensive First Teams. In addition, sixth man Danny Manning averaged 9.1 points and 4.4 rebounds per game off the bench, while Longley provided the team with 8.7 points and 5.7 rebounds per game, and George McCloud contributed 8.9 points per game off the bench.^[29]

The 7th-seeded Suns made the playoffs for the 11th consecutive season before being swept in the Western Conference First Round to the 2nd-seeded, and Pacific winner-Portland Trail Blazers, three games to zero.^{[30][31][32][33]} Following the season, Manning and Garrity were both traded to the Orlando Magic,^{[34][35][36][37]} who then traded Manning to the Milwaukee Bucks two weeks later,^{[38][39][40][41]} while McCloud signed as a free agent with the Denver Nuggets,^[42][43][44] Kleine signed with the Portland Trail Blazers,^[45] and Morris retired.