It will be a rematch of the highly anticipated fight in the spring of 2015, when Mayweather won.
"Floyd and I gave the world what remains the greatest fight in boxing history. The fans have waited long enough - they deserve a rematch," Filipino Pacquiao said in a joint statement with Mayweather.
"I've already beaten Manny once. This time it will be the same result," said the American.
Both Mayweather and Pacquiao have won several world championship belts but are past their best years.
Mayweather, who has never lost as a professional, announced this weekend that he would make a comeback after his last professional fight in 2017, against UFC fighter Conor McGregor.
Pacquiao's last match was in July 2025, when it ended in a draw against American Mario Barrios in a fight for the WBC welterweight world championship belt.
