The 49ers signed Campbell to a one-year deal Friday, Ian Rapoport of NFL Network reports.
The eight-year veteran is signing with the 49ers after spending the last three seasons of his career in Green Bay. Campbell struggled with injuries last year, appearing in just 11 games, but he still recorded 75 total tackles and defended one pass. The 30-year-old could very well have the opportunity to compete for a starting job in the 49ers' linebacker corps this offseason, especially with Dre Greenlaw recovering from the Achilles injury he suffered in the Super Bowl loss to the Chiefs.