During the fourth quarter of Super Bowl 50, Lynch tweeted out a photo of him hanging up his cleats.
The Seahawks did not respond to a message seeking comment, but Lynch's agent, Doug Hendrickson, confirmed to The Associated Press that the running back indeed plans to retire.
Seahawks owner Paul Allen and the organization's Twitter account both paid tribute to Lynch,who has the fourth-most rushing yards in team history.
It should come as no surprise that the media-shy running back signaled his retirement without words. ESPN's Adam Schefter reported earlier Sunday that Lynch has been telling friends he plans to retire. During an interview with 710 ESPN Seattle earlier this offseason, general manager John Schneider said he believed Lynch was leaning that way.
Seahawks cornerback Richard Sherman was one of Lynch's teammates who took the tweet as an announcement that the running back is finished.
Quarterback Russell Wilson, who spent the first four seasons of his career handing off to Lynch,weighed in to congratulate and honor his teammate.
Seahawks linebacker Bruce Irvin gave a humorous nod to his teammate's enigmatic temperament in a tweet.
The past season was a struggle for Lynch. He missed nine regular-season games and one in the playoffs after undergoing surgery associated with a sports abdomen injury on Nov. 25. Lynch had missed just one game the four previous seasons.
Lynch will turn 30 this offseason, and he reportedly considered retirement last year after dealing with back issues.
Lynch has been among the most productive running backs in the league since 2011, his first full season with the Seahawks after arriving from the Buffalo Bills in a midseason trade the year before. During those five seasons, Lynch finished third in rushing yards (5,774), second in first downs (294) and first in rushing touchdowns. His 51 touchdowns surpassed Adrian Peterson's second-place total by six.
Lynch had a way of elevating his game for the postseason. His six 100-yard playoff games fall short of only Terrell Davis and Emmitt Smith in NFL history.
In his nine-year career, Lynch has started 114 games and carried 2,144 times for 9,112 yards and 74 touchdowns (4.3 YPC).