Second rower Mannering, 25, has made well over 100 appearances for the club since making his debut in 2005 against Brisbane.
It means that the New Zealand international, who was appointed captain in 2010, is set to become the Warriors’ second longest serving player behind Awen Guttenbeil.
Mannering said he was relieved to have his future sorted before the Warriors kick off their NRL season against Manly on March 4.
“It’s a bit of a relief to have this sorted out early so all the focus is on football,” he said.
“I love being at the Vodafone Warriors. It’s a great club to be a part of and there’s plenty to be excited about for the future.
“I’m just looking forward now to starting the season. We’ve got such a huge game against Manly at Eden Park to start it off. It’s going to be a really big day for all of us.”
Head coach Brian McClennan said retaining Mannering was vital.
“Simon means so much to the Vodafone Warriors,” he said.
“This is where it all started for him and it’s so important he stays because of what he has to offer our team and our club right now and in the future.
“It’s also great that we were able to let our Vodafone Warriors members know about this first. They provide such wonderful support for our club.”