The 6-foot-3, 306-pound Wilson, who turns 27 on Sunday, was a seventh-round draft pick of the Green Bay Packers in 2010 out of East Carolina. In four seasons, he has played in 50 games, starting 11, and has 3 ½ sacks.
"It feels great to be a Raider," Wilson said in a team-issued release. "I’m excited to help the team win and ready to come make some noise."
He was limited to eight games last season -- he missed three games with an ankle injury but was a healthy scratch the other times -- after having a breakthrough 2012, in which he appeared in 11 games, seven starts, and had 37 tackles (18 solo), with 2 ½ sacks and a pass defensed.
Wilson also stepped up as a rookie during the Packers' four-game playoff run to the Super Bowl XLV title.
With the Raiders, Wilson is expected to be versatile enough to play both end and inside, though primarily as a run-stuffer on first and second downs.