The franchise began play in the 1988–89 season as an expansion team. After a period of mediocrity, the Heat gained relevance during the 1990s following the appointment of former head coach Pat Riley as team president. Riley constructed the high-profile trades of Alonzo Mourning and Tim Hardaway, which immediately propelled the team into playoff contention. Mourning and Hardaway led the Heat to four division titles, prior to their departures in 2001 and 2002. The team experienced renewed success after drafting Dwyane Wade in 2003.
Led by Wade and following a trade for former NBA Most Valuable Player (MVP) Shaquille O'Neal, Miami won their first NBA Finals in 2006, under Riley as head coach. After the departure of O'Neal two years later, the team entered into another period of decline for the remainder of the 2000s. Riley retained his position as team president, but was replaced as head coach by Erik Spoelstra. In 2010, the Heat signed former league MVP LeBron James and perennial NBA All-Star Chris Bosh, creating the "Big Three" along with Wade. During their four-year spell together, Spoelstra, James, Wade, and Bosh led the Heat to the NBA Finals in every season, and won back-to-back championships in 2012 and 2013. The trio would all depart by 2016, and the team entered another period of rebuilding. After acquiring All-Star Jimmy Butler in 2019, the Heat returned to the NBA Finals in 2020.
The Heat hold the record for the NBA's third-longest winning streak, 27 straight games, set during the 2012–13 season. Four Hall of Famers have played for Miami, while James won two consecutive NBA MVP Awards while playing for the team.