The Panthers did not release financial terms.
The 6-foot-2, 210-pound Avant spent his first eight seasons in the NFL with the Philadelphia Eagles.
Last season he started a career-high 13 games and had 38 receptions for 447 yards and two touchdowns. Those numbers were down from his previous three seasons in which Avant averaged 52 receptions and 633 yards receiving per year.
''We are happy to have Jason with the Panthers,'' Carolina coach Ron Rivera said in a press release. ''He provides a versatile player at receiver and brings good size as well as experience to the position.''
Avant becomes the third free agent wide receiver to sign with the Panthers this offseason.
After a 12-4 season in which they won the NFC South championship, the Panthers released their all-time leading receiver Steve Smith and lost Brandon LaFell, Ted Ginn Jr. and Domenik Hixon to other teams via free agency.
That left Panthers quarters Cam Newton without any wide receivers on the roster that he completed passed to last season.
A fourth-round pick in 2006, Avant has played in 116 during his career with 297 catches for 3,646 yards and 12 TDs.