Lynch had previously announced his intentions to retire after battling injuries last season. The move reduces the Seahawks' roster to 90 players.
Lynch joined the Seahawks after a 2010 trade with the Buffalo Bills. He started 77 of 82 games for Seattle and ranks fourth on the franchise list in rushing yards (6,347) and rushing attempts (1,457), second in rushing touchdowns (57) and third in touchdowns (65).
With the Bills and Seahawks, he totaled 9,112 rushing yards and 74 touchdowns on 2,144 carries.
If Lynch changes his mind about retirement, the Seahawks retain his rights. But the team appeared to be looking toward the future during last week's draft while selecting three running backs.