Jackson had been the club's longest-tenured player after signing as a rookie free agent in 2003. He started 72 of the 88 games he played for Philadelphia.
Justice was a second-round pick by the Eagles in 2006 and appeared in 47 games (31 starts).
Additionally, the Eagles re-signed defensive tackle Antonio Dixon, who missed most of last season with a torn triceps. He has recorded 62 tackles and three sacks in 35 games with Philly.