They also addressed one of the team's biggest needs by signing long-snapper Ryan Kuehl.
Terms of the deals were not disclosed, but ESPN reported Sunday that Hilliard, 26, one of the most highly-regarded receivers available on the free agent market, agreed to a five-year deal worth $12.5 million, including a $2.5 million signing bonus.
Hilliard played in only seven games last season because of a dislocated shoulder, suffered against Philadelphia, when Eagles safety Brian Dawkins crunched him as he stretched to catch a pass. He had 27 catches for 386 yards and two touchdowns before the injury.
Hilliard suffered a neck injury in his 1997 rookie season and played in just two games, but between 1998-2001, he averaged 57.5 catches, 789 yards, and nearly five touchdowns.
"I'm excited about having Ike back," said Giants Coach Jim Fassel, who was instrumental in making Hilliard the seventh overall pick of the 1997 draft. "Ike is a gamer. He is a true player. He makes plays when you need them to be made in the game. He's a guy that's meant a lot to this organization. He's made a lot of plays, and he's going to get great opportunities next year to make them."
Kuehl's arrival could end the costly carousal the Giants had last season at long snapper. The Giants used five snappers last season, including Trey Junkin, who was brought out of retirement, and made the ill-fated snap on the last play of the wild card playoff loss at San Francisco.
Kuehl, who made the Washington Redskins as an undrafted free agent defensive tackle in 1996, has spent the last four seasons with the Cleveland Browns.
"He's a consistent snapper, and he's a pro," Fassel said.