Rivera, who won a Super Bowl with the Bears in 1985 and is their former defensive coordinator, was introduced in Charlotte, N.C., as the team's fourth head coach, succeeding the fired John Fox.
"I'd like it to be an aggressive, physical football team," he told reporters.
Coincidentally, a teammate of his from the '85 championship team, Leslie Frazier, recently was named coach of the Minnesota Vikings after taking over on an interim basis during the season. Another teammate, Mike Singletary, was fired after two-plus seasons as San Francisco's coach.
Rivera, 49, was the defensive coordinator in Chicago from 2004-06, helping the Bears reach the Super Bowl in his third season. But he was cut loose after that and become linebackers coach under Norv Turner in San Diego.
He was appointed the Chargers' defensive coordinator midway through the 2008 season.
The Panthers were an NFL-worst 2-14 this season, prompting the coaching switch.