The Giants placed cornerback Michael Coe on injured reserve with a hamstring injury to make room for Hill on the 53-man roster.
Hill, who returned to practice this week, is coming off a four-game suspension for violating the NFL's policy on performance-enhancing drugs. He said the suspension was the result of a doctor's prescription for Adderall.
"I've got a lot of pent-up aggression that Iâve got to let out, and I'm just happy to contribute to the team in some way," Hill said.
Hill had seven tackles on defense and four on special teams during the season's first five games.
Coe has been dealing with hamstring injuries throughout the season. He did not play against the Philadelphia Eagles and had an MRI on his knee Thursday. The team said earlier this week he would not play against the Bengals.