Carr, 28, has played for the Oakland Raiders, Tennessee Titans and most recently the Baltimore Ravens. Last season, he played in nine games and started one game. He recorded 19 tackles to go along with three pass deflections.
Carr had his best season in 2010, starting all 16 games for the Ravens. He made 61 tackles, deflected eight passes, forced three fumbles and intercepted two passes.
The Vikings have been trying to improve their weak secondary this offseason, signing former Chicago Bears cornerback Zack Bowman on Monday to a one-year deal. Carr recently visited the Minnesota Vikings practice facility before signing.