"Jamal is a leader and a proven high-end player at his position," General Manager Brian Xanders said. "He has anchored some of the NFL's best run defenses during his career, and we are fortunate to add him to our roster."
Williams (6-foot-3, 348 pounds) is a 13th-year defensive lineman who spent his previous 12 NFL seasons with San Diego. He was selected by the Chargers in the second round of the 1998 NFL Supplemental Draft from Oklahoma State University.
In 148 regular-season games (122 starts), Williams has recorded 436 tackles (306 solo), including 13 sacks (55 yds.), one interception (14 yds.), 22 pass breakups, four forced fumbles and three fumble recoveries. He also has contributed 29 tackles (15 solo) in seven postseason starts.
Williams, who is tied for third in the NFL in Pro Bowl selections (3) and tied for second in first-team All-Pro honors (2) among defensive tackles since 2005, led the Chargers to a top-seven NFL ranking in run defense in seven of his 12 years with the club, including league-leading seasons in 1998 (71.3 ypg.) and 2005 (84.3 ypg.).
In 2008, he finished with the second most tackles in his career (67), including a personal-best 13 tackles for a loss, and was named San Diego's co-MVP, Defensive Player of the Year and Lineman of the Year.
Last season, he was named one of San Diego's 50 Greatest Chargers in a fan vote as one of three defensive tackles chosen for the 50th anniversary squad.
A first-team All-Big 12 selection as a senior at Oklahoma State, Williams attended Archbishop Carroll High School, in Washington D.C., and was born on April 28, 1976.