Cole visited the Seahawks on Friday -- the first day of NFL free agency -- and the two sides agreed to terms shortly afterward.
NFL.com reported the deal earlier Sunday. According to NFL Network's Adam Schefter , Cole's contract is worth $21 million with $6 million guaranteed.
Cole, 28, played the last five seasons for the Green Bay Packers, making eight starts and earning significant playing time in their defensive tackle rotation. His departure is a setback for the Packers, who struggled on defense last season but could point to Cole as one of their most consistent players.
The Associated Press contributed to this report.