Manningham spent the first four seasons of his NFL career with the Giants, helping them to Super Bowl success in 2011 before joining the San Francisco 49ers before the 2012 campaign.
However, the 27-year-old spent just two years in San Francisco before returning to the Giants, and he was quick to express his delight at being back with the team.
"I'm happy to be back. I'm real excited. It's just great to see everybody, be around familiar faces, knowing everybody in the past and just being comfortable around everybody," Manningham said in a statement.
"Once a Giant, always a Giant. That's how I feel. This is a very special place. I wanted to come back."
Manningham struggled with injuries last year, managing just nine receptions for 85 yards in his six games.