Also putting pen to paper were Jacob Lillyman, Suaia Matagi, Sione Lousi, Charlie Gubb, John Palavi, David Bhana, Sam Lisone, Solomone Kata and Brad Abbey.
Co-owner Eric Watson said Mannering's signing was not only one of the longest but also one of the most significant in the club's history.
Lillyman had been re-signed to the end of the 2017 season and back-rower Lousi to the end of 2016 bringing to 12 the number of players who have extended their stays in recent times.
"This a signal of how much the Warriors mean to Simon, Jacob, Sione and all the other players who have re-signed,'' he said.
"It's also a tribute to the work Dean Bell (general manager football operations) is doing with Wayne Scurrah (chief executive) with our recruitment.
"Simon's signing is a fantastic coup and a huge boost for the club. He is exceptional across the board as our record-holding captain, a player of the highest order and also a person of tremendous quality.
"I'm elated he is extending his career with us to what will be 14 seasons. Only a few in the game today can measure their dedication to one club in such terms.''
The 27-year-old Mannering, off contract at the end of this season, had attracted significant interest from other clubs.
"This is the biggest contract of my career because it could possibly be my last,'' he said. "I love this club and always will. I'm keen to be a part of our future and have the greatest faith in the direction to the club is heading. We have much to offer this season and in years to come.
"It's not just about football, though. I also have my family to consider. That was a big part of the decision and I'm really happy it has all worked out.''
