Ginn, the ninth overall pick in the 2007 NFL draft, is coming off a three-year stint with the 49ers.
Both players signed one-year deals that were announced Thursday.
Munnerlyn and Mitchell are the latest moves to improve a secondary looking to replace longtime starting cornerback Chris Gamble, who was released in a salary cap move. Carolina previously signed unrestricted free agent cornerbacks D.J. Moore and Drayton Florence.
Panthers coach Ron Rivera says, "Mitchell should provide competition in the secondary, and we know Captain is a tough, hard-nosed competitor capable of making big plays."
Munnerlyn played in all 16 games with 11 starts for the Panthers in 2012.
Mitchell joins the Panthers after playing the first four seasons of his career with the Raiders. He has nine career starts.
Information from The Associated Press and ESPN NFL Insider Adam Schefter was used in this report.