Avant was cut by the Eagles on March 4 after eight NFL seasons in Philadelphia.
The former Eagles fourth-round draft pick has caught 297 passes for 3,646 yards for his career.
Avant had 38 receptions for 447 yards and two touchdowns last season, dropping from three consecutive seasons with at least 50 receptions.
He joins a receiving corps that also includes newcomers Jerricho Cotchery and Tiquan Underwood.
"We are happy to have Jason with the Panthers," Panthers coach Ron Rivera said. "He provides a versatile player at receiver and brings good size as well as experience to the position."
Follow me on Twitter: @RavensInsider
Aaron Wilson covers the Ravens for The Baltimoer Sun