Clemons, 30, led the Seahawks in sacks with 11 last season. He was entering the final year of his contract and had been seeking an extension. Clemons skipped a mandatory minicamp last month, triggering a contract clause that reduced his 2012 base salary from $4 million to $3 million. The new deal makes that reduction a non-issue.
Contract terms were not immediately available.
At 6-foot-3 and 254 pounds, Clemons fits the pass-rushing role coach Pete Carroll envisioned for him when Seattle traded Darryl Tapp to the Philadelphia Eagles for Clemons and a fourth-round choice in 2010.
Seattle finished last season with 33 sacks, tied for 19th in the NFL. Clemons collected one-third of them, reflecting the team's need for an additional top-flight pass-rusher, which they hope they attained in selecting Bruce Irvin in the first round of this year's draft.