The deal is reportedly worth up to $5.5 million including incentives, according to Mike Florio of ProFootballTalk.
Arizona worked out Crabtree earlier in August, but the two sides reportedly couldn't agree to terms despite the team extending an offer.
The Baltimore Ravens released the 31-year-old in February, just one season into his three-year deal.
Crabtree racked up 607 yards and three touchdowns on 54 receptions but saw his role diminish after the team installed Lamar Jackson as starting quarterback midseason.
The veteran will now provide much-needed experience for Arizona's receiver corps.
Arizona made room for Crabtree by releasing former Chicago Bears first-round pick Kevin White on Wednesday.