Foote confirmed the one-year deal to ESPN.
Foote spent 11 of his 12 seasons with the Pittsburgh Steelers before he was released in March after missing all but Week 1 with a ruptured right biceps. He spent the 2009 season with the Detroit Lions.
With the exception of his stint with the Lions, Foote's tenure in Pittsburgh overlapped with Arizona head coach Bruce Arians' eight years on the Steelers' coaching staff.
Foote won two Super Bowls in Pittsburgh, including Super Bowl XLIII over the Cardinals.
Foote, who turns 34 in June, started 119 of 172 games throughout his career. He has 705 tackles (472 solo), 23 sacks and three interceptions.
He also gives the Cardinals a proven option should Daryl Washington face a suspension for violating the NFL's personal conduct policy after pleading guilty to the aggravated assault of a former girlfriend who is the mother of his daughter.
Foote made $2.5 million last season, according to ESPN Stats & Information.