The 36-year-old spent his entire 14-year career with the Royals after they selected him second overall in 2005.
"Alex's commitment to his teammates through his dedication and work ethic, plus the way he played the game with everything he had every single day was unlike anything I've ever seen," former Royals manager Ned Yost said, according to Joel Goldberg of Fox Sports Kansas City. "He was the perfect teammate. Congratulations Alex."
Entering Thursday, Gordon owns a career .257/.338/.411 slash line with 190 home runs, 749 RBIs, and 113 steals.
The three-time All-Star, who was an integral member of the Royals' 2015 World Series championship team, also won seven Gold Gloves and amassed 111 defensive runs saved throughout his career.
Gordon earned more than $117 million, according to Baseball-Reference.