Crocker, 34, recorded 37 tackles, two interceptions and 1.5 sacks in 12 games for the Bengals last season.
He had played Cincinnati since October, 2013. Mike Zimmer, the current Vikings head coach, served as the Bengals' defensive coordinator from 2008-13. Zimmer also coached Crocker as Atlanta's defensive coordinator in 2007.
Drafted in the third round in 2003 by Cleveland, Crocker has played in 151 games over 11 seasons.
To make room on the roster for Crocker, the Vikings released undrafted rookie defensive end Rakim Cox.
Minnesota went 5-10-1 last season and finished in last place in the NFC North. The team opens the 2014 regular season Sep. 7 at St. Louis.
- Chris Johnson