The bout will be shown worldwide on Netflix, with the event being promoted as a collaboration between Saudi boxing powerbroker Turki Alalshikh's The Ring and UFC chief Dana White.
The event will be shown live on Netflix, while the pair will come face-to-face at a news conference at London's British Airways Arc on Wednesday, September 30th.
"I am inspiring a generation," Joshua, 36, posted on Instagram. Fury, 38, is yet to comment on the announcement.
"Two of the best heavyweights of this generation, finally in the ring together," said Alalshikh. "This will be one of the biggest fights in boxing history. I am very happy to make this fight happen for the fans."
Both fighters reportedly signed contracts in April, but it has since taken months to agree on a date and venue. Netflix and the Saudi organisers first wanted Madison Square Garden in November, which would have put the fight in US prime time. That plan fell through because Joshua's contract reportedly requires the fight to take place in the UK. Fury's contract has no such clause.
Wembley Stadium was the next option, but it has a 00:00 CET curfew. A later finish required extra approvals, and an open-air crowd in December weather posed an additional risk.
Cardiff solved both problems, with the Principality Stadium boasting a retractable roof, and the Welsh Rugby Union has said a late finish is not a problem. Ring walks are expected at around 02:00 CET, which is 20:00 on the US East Coast.
The stadium has hosted late-night boxing before when Welsh legend Joe Calzaghe's super-middleweight unification fight with Mikkel Kessler in November 2007 started in the early hours to suit American television.
Joshua has fought twice at the venue, stopping Carlos Takam there in October 2017 and outpointing Joseph Parker in March 2018 to win the WBO title, with crowds of close to 80,000 both nights. Fury has never fought in Cardiff.
"Forever indebted to the UK public for their support of Anthony Joshua. We couldn't have got this over the line without you," said Joshua's promoter Eddie Hearn.
Talks over the super fight have been ongoing for the better part of a decade. In 2021, the pair agreed a two-fight deal for Saudi Arabia that August, but an arbitrator ruled that Fury had to face Deontay Wilder for a third time first. A year later, Fury offered Joshua a December date in Cardiff, which was accepted, but talks collapsed before any contracts were signed.
Both men have lost to Oleksandr Usyk since then, with the Ukrainian icon beating Joshua twice for the unified titles in 2021 and 2022, as well as beating Fury twice in 2024. Daniel Dubois knocked Joshua out in five rounds at Wembley in September 2024.
In December 2025, Joshua stopped Jake Paul in the sixth round in Miami. Ten days later, he was injured in a car crash in Nigeria that killed two of his close friends.
AJ's first fight after the crash came in Jeddah in July, when Kristian Prenga knocked him down twice in the first round before Joshua stopped him in the second.
Fury retired in January 2025 after his second defeat to Usyk. He came back to outpoint Arslanbek Makhmudov at Tottenham Hotspur Stadium in April in front of 64,500 fans. In July, 'the Gypsy King' stopped 46-year-old Mariusz Wach in seven rounds in Pattaya, Thailand, the night before Joshua fought Prenga.
Fury goes into the fight with a record of 36-2-1 (25 KOs), and Joshua's record is 30-4 (27 KOs).
The build-up has already turned bitter. While the venue was still being argued over, Fury posted videos calling Joshua a "little coward" with a "paper chin". He accused Joshua of stalling and suggested he might face Usyk again instead. Hearn said Fury was "afraid to lose", and the promoter has also admitted the two contracts are not identical. "What's in AJ's contract is not necessarily in Tyson Fury's contract," he said.
UFC chief White's involvement is also notable. He fronts Zuffa Boxing, and Hearn had previously said he did not want White promoting the fight.
"For more than a decade, boxing fans have been clamouring for the heavyweight showdown between Tyson Fury and Anthony Joshua. Together, they bring 66 wins, 52 knockouts and multiple heavyweight world titles into the ring," White said.
"On December 11th, two of the biggest heavyweights of this generation finally collide - and the winner will take a significant place in heavyweight history."
The undercard is set to be announced at a later date.