The franchise began play in 1968 as an expansion team, and their early years were shrouded in mediocrity, but their fortunes changed in the 1970s after partnering Dick Van Arsdale and Alvan Adams with Paul Westphal; the team reached the 1976 NBA Finals, in what is considered to be one of the biggest upsets in NBA history. However, after failing to capture a championship, the Suns would rebuild around Walter Davis for a majority of the 1980s, until the acquisition of Kevin Johnson in 1988.
Under Johnson, and after trading for perennial NBA All-Star Charles Barkley, and combined with the output of Tom Chambers and Dan Majerle, the Suns reached the playoffs for a franchise-record thirteen consecutive appearances and remained a regular title contender throughout the 1990s, and reached the 1993 NBA Finals. However, the team would again fail to win a championship, and entered into another period of mediocrity until the early part of the 2000s.
In 2004, the Suns signed free agent Steve Nash (who had blossomed for the Dallas Mavericks after being traded from Phoenix six years earlier), and returned into playoff contention. With Nash, Shawn Marion, and Amar'e Stoudemire, and under head coach Mike D'Antoni, the Suns became renowned worldwide for their quick, dynamic offense, which led them to tie a franchise record in wins in the 2004–05 season. Two more top two Conference placements followed, but the Suns again failed to attain an NBA championship, and were forced into another rebuild. After ten consecutive seasons without a playoff berth, the Suns reached the 2021 NBA Finals after acquiring Chris Paul, forming a trio with their young core Devin Booker and Deandre Ayton.
The Suns own the NBA's seventh-best all-time winning percentage, and have the second highest winning percentage of any team to have never won an NBA championship. 10 Hall of Famers have played for Phoenix, while two — Barkley and Nash — won NBA Most Valuable Player (MVP) while playing for the team.