Amor has signed on for three more years in an extension to his current deal, while Wilkin has agreed a new, two-year deal.
“I’m delighted that both players have agreed to stay at the club,” said Saints coach Keiron Cunningham.
“They are integral to what we do here and provide leadership and professionalism to the younger players in the group.
“Kyle is at the hub of our pack and is in his prime. He has been superb for us over the last couple of seasons and is one of our most consistent performers.
“What I like about Kyle is he is keen to learn and develop and I’m sure if he continues to do that he will break onto the international scene.
“Jon has been an important part of the Saints over the last 14 years and his leadership is second to none. He sets a superb example to all the players here and leads from the front on the field.
“His attitude is first rate as his workrate and ability to adapt to whatever is thrown his way.”
Amor, 29, is determined to use his new deal to help establish himself at international level.
“I’m really happy to commit myself to the club until 2020,” he said.
“It was an easy decision. Both my family and I are really happy in St Helens and we enjoy being here.
“I now want to try and kick on and gain international recognition and I believe I am at the right place to do that.
“This year’s squad is the strongest it has been over the last few years and I’m looking forward to getting started.”
Veteran utility player Jon Wilkin is pleased to have sealed his immediate future.
“I have been part of this club for 14 seasons and I am delighted to stay here,” he said.
“It is a real honour to captain this team and help develop the next generation of leaders that are coming through.
“I am excited about 2017 and what is on the horizon for this group.”