Teams are not allowed to talk deals with free agents until March 11, and no deals can be announced until the start of the new league year on March 13.
The Jaguars are expected to release quarterback Blake Bortles and install Foles as their starter. Jacksonville will have to pay $6.5 million of Bortles' 2019 salary, which was fully guaranteed when he signed his current contract last year.
The Jaguars' expected signing of Foles was first reported by Philly.com.
Philadelphia Eagles general manager Howie Roseman said Wednesday that the team would not place the franchise tag on Foles, leaving him a free agent.
"He deserves an opportunity to lead a team," Roseman said.
The organization had been entertaining the idea of placing the tag on Foles to facilitate a trade, but the decision likely means they were unable to find a deal that worked. By letting him walk, the Eagles are expected to receive a compensatory pick as high as a third-rounder in 2020.
Foles' potential market shrank when the Denver Broncos traded for Joe Flacco, leaving Jacksonville as Foles' only known suitor. The Jaguars hired John DeFilippo as their offensive coordinator in January. DeFilippo was Foles' quarterbacks coach with the Eagles in 2017.
Foles' primary objective this offseason was to find a team he could call his own following two incredible seasons as Carson Wentz's backup. He opted out of his contract with the Eagles by paying them back $2 million in February.
"I would love to lead a team," Foles said at the close of the 2018 season. "The starter thing, leading a team, impacting a locker room ... that's why we play the game -- to impact people, to create an atmosphere."
Originally drafted by the Eagles in the third round in 2012, Foles was traded to the St. Louis Rams before the 2015 season after a few up-and-down years in Philly and contemplated retirement following a difficult year in St. Louis. Instead, he rejoined coach Andy Reid as a backup with the Kansas City Chiefs before returning to Philly in a similar role in 2017.
A signing that received little attention at the time proved to be one of the most important in Eagles history, as Foles took over for Wentz down the stretch that season and helped the team to its first Super Bowl title. He completed 73 percent of his passes -- an NFL single-season record -- and threw six touchdowns with one interception during that playoff run en route to being named Super Bowl MVP.
He proved that it was no fluke by saving the Eagles' season a second time this past year, helping them to three straight wins in place of an injured Wentz to close the regular season and a road victory over the Chicago Bears in the wild-card round.
The Jaguars finished 5-11 in 2018, and owner Shad Khan brought back executive VP of football operations Tom Coughlin, GM Dave Caldwell and coach Doug Marrone for 2019, but he said he expects significant improvement. Coughlin and Caldwell apparently believe that signing Foles instead of drafting a rookie gives them the best chance to return to the playoffs.
Although the Jaguars' defense did not sack the quarterback and force turnovers in 2018 at the rate it did in 2017, the unit still finished in the top five in total defense, pass defense and scoring defense. All but two -- and possibly three -- starters are expected to return in 2019.
With Foles as the starter, the Jaguars can concentrate on adding playmakers on offense at tight end and receiver and addressing the right side of the offensive line in the early rounds of the draft.
Foles, 30, has completed 62 percent of his passes in 54 career games, with 68 touchdowns and 33 interceptions. He has the sixth-best career postseason passer rating (98.8) in NFL history.
ESPN's Michael DiRocco contributed to this report.