Berry, 26, was diagnosed with Hodgkin lymphoma disease – a blood cancer – back in December 2014, after complaining of chest pain in a game against the Oakland Raiders the month before. He left almost immediately to undergo treatment at Emory University in Atlanta.
In June he completed his treatment, but it remained unclear when he could return to football.
Then on Tuesday, the Chiefs announced that the three-time Pro Bowler would be back in time to start training camp.
"He's kept himself in good shape, believe it or not," Chiefs coach Andy Reid told the Associated Press. "He's really done a good job there."
News of his return spread quickly online, with fans and fellow NFL players Tweeting well wishes.
St. Louis Rams defensive end Chris Long wrote: "Good for Eric Berry!!! There's some great news for once on my timeline."
Good for Eric Berry!!! There's some great news for once on my timeline.— Chris Long (@JOEL9ONE) July 29, 2015
Arizona Cardinals defensive back Patrick Peterson wrote: "True warrior!! Welcome back E!"
True warrior!! Welcome back E! https://t.co/OiXCcKGDyE— Patrick Peterson (@RealPeterson21) July 29, 2015
"Great news about Eric Berry!!" Tweeted New York Giants cornerback Prince Amukamara.
Great news about Eric Berry!— Prince Amukamara (@PrinceAmukamara) July 29, 2015
Berry will be on the field in St. Joseph, Missouri, on Wednesday with a small group of Chiefs, including rookies, quarterbacks and players coming off injuries.