PWInsider's Mike Johnson first reported the agreement.
Orton appeared to tease a possible move to All Elite Wrestling in an Instagram post on Oct. 21. He stood next to a small sign reading "Elite Level" and wrote the caption, "tick tock tick tock," while tagging a number of wrestlers including Chris Jericho and Cody.
Fightftul's Sean Ross Sapp (warning: video contains profanity) reported in February that Orton "has been openly discussing his willingness to speak with All Elite Wrestling."
Although AEW is presenting an alternative for disaffected WWE stars when their contracts end, the idea of Orton jumping ship for the competition always appeared fanciful.
The 39-year-old has spent almost the entirety of his in-ring career with WWE, making his television debut in April 2002.
He was almost immediately identified as a foundational piece of the roster, joining Evoution and then becoming the youngest world heavyweight champion in history (24) when he beat Chris Benoit as SummerSlam 2004.
Although Orton's last world title win was at WrestleMania 33 in April 2017, he has reached a level where he generally doesn't need to hold the WWE Championship or Universal Championship to be near the top of the card.
Especially with John Cena focusing more on his acting career, nobody in the WWE locker room can command more respect as a tenured veteran than Orton, and that will continue to be the case going forward.