The deal is worth up to $6 million with $3 million in guarantees, NFL Network's Mike Garafolo reports.
Peters will replace Brandon Brooks in the starting lineup after the three-time Pro Bowler was lost for the season with a torn Achilles.
The 38-year-old had options early in free agency as a tackle, Peters' agent, Vince Taylor, told Jeff McLane of the Philadelphia Inquirer. "His heart is just in Philly," Taylor said.
Youngsters Matt Pryor, Nate Herbig, and Jack Driscoll were initially expected to compete for a shot to replace Brooks in camp, but the Eagles instead opted for an established presence between Jason Kelce and Lane Johnson.
The signing also likely pencils in 2019 first-rounder Andre Dillard as the team's Week 1 starting left tackle, though Peters provides insurance at the position.
Peters has been one of the NFL's premier blockers since Philadelphia acquired him in 2009. He's been named to nine Pro Bowls and earned two first-team All-Pro nods in his 16-year career.