Hill completed his six-game suspension and practiced this week for the first time in the regular season.
It's unknown how much Hill will play Sunday against the Atlanta Falcons, but he addresses a position of need. The Ravens' safeties have struggled in coverage this season.
Hill was the third-rated safety last season when he started for the Giants, according to Pro Football Focus.
The Ravens didn't activate nose tackle Terrence Cody from the Physically Unable to Perform list. They have two more weeks before having to make a decision with Cody's status.