Seattle announced the signing of Adams on Thursday night.
Adams spent last season with the Oakland Raiders but he's not unfamiliar with the Seahawks. Adams spent part of the 2011 season with Seattle and appeared in one game.
With the Raiders the past two seasons, Adams appeared in 31 games with four starts. He had two interceptions.
Seattle lost cornerbacks Walter Thurmond and Brandon Browner and safety Chris Maragos during the early stages of free agency.