Impact Wrestling was formed as NWA: Total Nonstop Action in May 2002. Later that same year, TNA was granted control over the NWA World Heavyweight and World Tag Team Championships by the National Wrestling Alliance (NWA) governing body; subsequently becoming an official NWA territory as NWA-TNA. On June 19, 2002, NWA-TNA held its first show; a weekly pay-per-view event. The main event of the telecast was a twenty-man Gauntlet for the Gold match in which 20 men trying to throw each other over the top rope and down to the floor in order to eliminate them, until there were two men left who wrestle a standard match to become the first ever TNA-era NWA World Heavyweight Champion. Ken Shamrock defeated Malice to win the vacant championship with Ricky Steamboat as the special guest referee at the event.
was the first TNA World Heavyweight Champion, seen here hoisting the first title belt design (left)
The NWA World Heavyweight and World Tag Team Championships were contested for in TNA until the morning of May 13, 2007. On that day, NWA's Executive Director Robert Trobich announced that the NWA were ending their five-year agreement with TNA, which had allowed them full control over both titles. Trobich went on to state that effective that morning, then-NWA World Heavyweight Champion Christian Cage and then-NWA World Tag Team Champions Team 3D were stripped of their respective championships. The alleged motivation behind these actions was because Cage refused to defend the NWA World Heavyweight Championship against wrestlers from NWA territories. That same day, TNA were scheduled to produce their Sacrifice event, in which both Cage and Team 3D were to defend their respective championships. On the card, Cage was scheduled to defend the NWA World Heavyweight Championship against Kurt Angle and Sting in a match involving three competitors, also known as a three-way match.
That night, the onscreen graphic used to refer to the champions and their respective championships credited both Cage and Team 3D as still being NWA champions. However, the ring announcers for the encounters proclaimed the matches as being strictly for the "World Heavyweight Championship" and the "World Tag Team Championship". Angle defeated Cage and Sting to win the World Heavyweight Championship.
TNA held a set of tapings for the next two episodes of Impact! on May 14, with the episodes set to air on tape delay on May 17 and May 24. At the first taping, Angle came to the ring with the new TNA World Heavyweight Championship belt and announced that he was the "new TNA World Heavyweight Champion". TNA commentator Mike Tenay announced when Angle made his way to the ring that Management Director Jim Cornette, TNA's on-screen authority figure at the time, "made the decision that due to TNA's growing worldwide exposure, the company needed to have its own TNA title belts"; thereby not acknowledging the NWA ending their agreement with TNA and giving a storyline explanation as to why the championship was created. Later on during the broadcast, Cornette stripped Angle of the TNA World Heavyweight Championship due to a controversial finish to the match at Sacrifice. Cornette then announced the championship would be contested for at TNA's Slammiversary on June 17, 2007 in a King of the Mountain match—a match which involves five participants racing to gain a pinfall or submission to become eligible to hang a championship belt to win. On May 15, 2007, Jeremy Borash unveiled the TNA World Heavyweight Championship belt on that day's edition of TNA's online podcast TNA Today.
The five participants for the King of the Mountain match were determined in a series of standard wrestling matches that took place on Impact! leading up to the event, with Angle defeating Rhino in the first bout to gain entry on the May 17 episode of Impact!. On the May 24 episode of Impact!, Samoa Joe defeated Sting to become the second participant. The third qualification match was held on the May 31 episode of Impact! between A.J. Styles and Tomko, which Styles won. The next bout pitted Chris Harris against James Storm on the June 7 episode Impact!, which ended in a double disqualification, therefore neither man advanced to the King of the Mountain match. The final qualification match was won by Christian Cage over Abyss on the June 14 episode of Impact!. Angle ended up winning the King of the Mountain match at Slammiversary over Joe, Cage, Styles and Harris, who was a mystery participant chosen by Cornette, to become the "undisputed TNA World Heavyweight Champion".
In early 2017 After TNA rebranded as Impact Wrestling, the name of its flagship show, the TNA World Heavyweight Championship changed its name to the Impact Wrestling World Heavyweight Championship to reflect the name changes of the company.
At Slammiversary XV, GFW Global Champion Alberto El Patron defeated Impact Wrestling World Heavyweight Champion Bobby Lashley to unify the titles, with the GFW Global Championship being dropped and the Impact World Heavyweight Championship changing its name to the Unified GFW World Championship as Impact Wrestling began rebranding once again as GFW. In September 2017, GFW reverted their branding to Impact Wrestling.