The WBC champion said in April, after beating compatriot Dillian Whyte (34) at Wembley stadium, that he had promised his wife he would retire.
His promoter Frank Warren told Talksport radio at the weekend, however, that Fury had 'itchy feet' and wanted to get back in the ring.
"I've decided to come back to boxing because I can be the first heavyweight champion in history to have two trilogies, one with Deontay Wilder and a second one with Derek Chisora," Fury said on Instagram.
"I always said I'd fight Derek Chisora at the end of my career and here we are breaking all records again and setting precedents."
Undefeated Fury drew his first fight with Wilder for the WBC title in 2018 but beat the American in rematches in 2020 and 2021. He beat Chisora in 2011 and 2014.
Chisora is now 38 and had looked to be in the twilight of his career until he beat Bulgarian Kubrat Pulev on a split decision in London last month for the vacant WBA International title, a belt well below a world title.
Fury will also be waiting on the outcome of a rematch between compatriot Anthony Joshua and Ukraine's WBA, WBO, IBF and IBO champion Oleksandr Usyk in Jeddah, Saudi Arabia next week.
The WBC champion said last month he would be willing to fight Joshua in England provided the bout was free to watch and attend.
Fury said on Instagram he had hired featherweight Isaac Lowe as trainer.
"He knows me better than anyone on the planet and we're a great team," said Fury.
