"These past two months I've realized my place is still on the field and not in the stands. That time will come. But it's not now. I love my teammates, and I love my supportive family. They make it all possible. I'm coming back for my 23rd season in Tampa. Unfinished business LFG," Brady, 44, announced the news on Twitter.
Brady retired from American football on Feb. 1.
His latest club Tampa Bay Buccaneers, and the NFL both confirmed his return.
The Buccaneers said they are "ecstatic" over Brady's comeback.
Brady spent 22 seasons, playing for the New England Patriots in 2000-2019, and the Buccaneers then.
He joined the Buccaneers in 2020 to win the Super Bowl LV, the 55th playoff championship game.
Six of Brady's Super Bowl championships were with the Patriots, while his final victory came with the Buccaneers last year.
During his career, the US quarterback has been named Super Bowl MVP (most valuable player) five times and NFL MVP thrice.
The 2022 NFL regular season will kick off on Sept. 8.