The team did not release terms of the deal.
Barnidge, a 6-foot-5, 247-pound tight end, figures to contend for playing time with two other young tight ends: Jeff King and Dante Rosario.
Barnidge, a first-team All-Big East selection in 2007, played in 47 games with 29 starts for Louisville. He made 108 receptions for 1,491 yards and 17 touchdowns.
Also, Carolina waived fullback Breyone Evans, cornerback Cortney Grixby and wide receiver Damon Morton. All three players were signed as undrafted rookie free agents on May 2.