Avant, who will turn 31 this month, adds another veteran as the Panthers try to replace their top four wide receivers from last season.
"He provides a versatile player at receiver and brings good size as well as experience to the position," coach Ron Rivera said of Avant in a statement released by the team.
The 6-foot-2, 210-pound Avant spent the past eight seasons with the Eagles. Set to count $4 million against the salary cap, he was cut last month.
The former Michigan star started a career-high 13 games last season. He finished with 38 catches for 447 yards and two touchdowns. He averaged 52 catches and 633 yards in his previous three seasons. Avant has 297 career catches for 3,646 yards and 12 touchdowns.
The Panthers, who have the No. 28 pick in first round of the May draft, are expected to use at least one of their first two or three picks on a wide receiver. Avant is more of a role player.
Rivera said recently at the NFL owners meeting in Orlando, Fla., that he wasn't concerned that the team might go into the season without a bona fide No. 1 receiver.
"The thing that we had to look at is we have a good group of young guys that we feel need to get opportunities," Rivera said. "We've got the draft, and there's no secret that at some point if we've got a chance to draft a wide receiver we are going to do it."
The Panthers released Steve Smith, their all-time leading receiver, early in free agency. They lost their other top four receivers -- Brandon LaFell (New England Patriots), Ted Ginn Jr. (Arizona Cardinals) and Domenik Hixon (Chicago Bears) -- in free agency.