The move, which came after the Chiefs wrapped up the second week of voluntary workouts, saves them $10 million in salary-cap space because Maclin was cut after June 1; they had just $3.5 million available before.
Maclin tweeted shortly after the surprise move was announced.
Crazy business this is...appreciate y'all #ChiefsKingdom— Jeremy Maclin (@jmac___19) June 2, 2017
"These decisions are never easy, especially with a player like Jeremy, who I've grown close with on and off the football field over the years," said Chiefs coach Andy Reid, who also coached Maclin with the Philadelphia Eagles. "I have a lot of respect for the way he goes about his business and how he handles himself as a professional. I wish him the best of luck moving forward."
Maclin, 29, signed a five-year, $55 million contract with Kansas City in 2015. With his release, the Chiefs now have just $7.7 million allocated to 11 wide receivers.
The team forfeited a third-round pick in 2016 and a sixth-round pick this year for tampering with Maclin when he was a free agent in 2015.
Kansas City has no clear-cut candidate to be its No. 1 receiver after releasing Maclin. Tyreek Hill was the team's leading wide receiver last year with 61 receptions, but the Chiefs have been hesitant to use him as a full-time receiver because he gets a lot of work as a running back and a kick returner. The most likely candidate is Chris Conley, a third-round draft pick in 2015. Conley caught 44 passes for 530 yards and zero touchdowns last season.
The Chiefs now have four wide receivers -- Hill, Conley, Albert Wilson and De'Anthony Thomas -- who have caught a pass in an NFL game. They have combined for 251 regular-season catches and 12 receiving touchdowns. Maclin has 474 regular-season catches and 46 touchdowns in his career.
Information from ESPN's Adam Schefter and Adam Teicher and The Associated Press was used in this report.