The Panthers announced the ceremonial signing Tuesday.
Stewart, 32, played the first 10 seasons of his career for the Panthers, after being selected as the No. 13 overall pick in the 2008 NFL Draft. The Oregon product made the Pro Bowl in 2015 after piling up 1,088 yards from scrimmage and seven touchdowns.
Stewart scored 10 touchdowns in his first NFL season. His sophomore campaign included 1,272 yards from scrimmage and 11 scores for the Panthers. Stewart and the Panthers reached the Super Bowl in 2016.
The 11-year veteran signed a two-year, $6.9 million contract with the New York Giants in free agency before the 2018 season. Stewart had just six carries for 17 yards in three games last season. The Giants declined to pick up Stewart's 2019 option in February.
Stewart retires with 8,630 yards from scrimmage and 58 touchdowns in 134 career appearances. He is the Panthers' franchise leader in rushing yards.