The deal is reportedly worth around $1 million a season.
But he has not effectively recommitted himself to the Giants for the rest of his career, where he is widely tipped to become the club’s next captain.
Coniglio was elated to remain a one-club player.
“This club has become home for me and in the end the culture and the opportunity are undeniable,” he told the club website.
“I’m just thrilled to be a GIANT for life and keen to continue on our path to becoming an even greater club. For me that’s the biggest driver and something I’ll aspire to do with my next seven plus years here.
“Clearly I had a lot to weigh up given I was looking to make a long-term commitment. In the end the opportunity here at the GIANTS to do something unique with some incredible people was just too great to turn down.”
Giants coach Leon Cameron was thrilled to see one of the club’s inaugural players remain at the helm.
“It’s no surprise to anyone at our football club that Stephen is so highly valued across the AFL,” Cameron said.
“There is no doubt our players walk taller when he’s by their side and his focus on giving back to the game is extraordinary.
“By pledging his long-term future to the GIANTS he’s speaking volumes as to where this club is headed and we’re delighted he’ll be central to that for many years to come.”