Terms were not disclosed.
Selected in the sixth round (192nd overall) of the 2015 draft by the Chargers out of Arkansas, Philon worked himself into a starting role as a defensive tackle in 2018. He recorded 33 combined tackles and four sacks in 13 starts. He played a full 16-game season for the second time in his four-year NFL career.
Philon, who turned 25 in January, finished with 80 combined tackles, 9.5 sacks, two forced fumbles and two pass breakups in four seasons with the Chargers, playing in a total of 54 games.
In addition to signing Philon, the Cardinals also announced that exclusive rights free-agent tight end Ricky Seals-Jones signed his one-year contract for the 2019 season.
Seals-Jones had 34 receptions for 343 yards and a touchdown for the Cardinals last season.
ESPN's Eric D. Williams contributed to this report.