Massey’s previous contract was due to expire in November, but he is now committed to the club until the end of 2022.
The 31-year-old made his first team debut in 2007 and Monday’s visit of Hull KR will be his 252nd appearance for Tigers.
“I am obviously over the moon because I’ve made it no secret that I wanted to stay here,” Massey said.
Leeds United ‘would have taken’ four points from two games according to Alan Shearer
Leeds United U21 2-2 Norwich City U21 highlights: Joseph and Perkins score again
Rodrigo makes 'sleeping' Leeds United admission and declares action plan after Whites punishment
Leeds United ‘have not’ approached pair but in transfer ‘talks’
Leeds United in ‘talks’ with MLS star as Man Utd eye deal for Whites goalkeeper
“This next two years is going to be big for me and it will take me to near the end of my career.
“I’ve said if it was possible I’d like to finish my career here and this contract might take me to that.
“I am proud to play for this club and I feel privileged to pull the shirt on every week.”
Lee Radford will take over from Daryl Powell as Tigers’ coach at the end of this season and Massey confirmed he has already spoken to the in-coming boss.
“Not so much has to change, but some fresh ideas and a different sort of game plan that he will probably bring is exciting,” Massey added.
Radford said Massey will be an integral part of his team for the next two years.
He noted: “He optimises what Castleford is all about really.
“He is honest, hardworking and does things that the untrained eye doesn’t see.
“He’s really tidy in and around the ruck and it’s because of players like him that Castleford have been as successful as they have been in seasons gone by.
“I’m really looking forward to working with him.”
Powell was also delighted for Massey, who he reckons has been one of Tigers’ best players this year.
“First and foremost, as a bloke he is top-class,” Powell said.
“He is Castleford through and through.
“He has been one of the players I have been able to rely on so much during my time at Castleford and I am pleased for him, to get his future settled and for Castleford as well.
“He is part of the fixtures here and I think he has been at his best this year.
“He has obviously wanted to earn a new contract and he has been one of our best front-rowers.
“Generally, if I am picking a team I can’t think of too many times throughout the last eight years when I haven’t picked Nathan Massey if I am looking for our best team.
“I think that probably sums it up.”
Of what Massey brings to the team, Powell added: “The things that are regarded pretty highly in an environment are the little hard work things that you don’t always see - the kick pressure in particular.
“He has probably been our best since I’ve been at the club.
“Because the boys have been defending - and usually the middle-unit players have to make a lot of tackles - to then at the end of that put pressure on the guy who’s kicking the ball, which then supports the man catching the ball, they’re the little things that are valued so highly.
“He does big minutes and you don’t always see that in middle-unit players because they get put under a lot of stress.
“His third-man tackling, from a defensive perspective, is consistent, he is honest as the day is long.
“That is so critical to success and Nathan is one of the most honest guys I know.”
Support the YEP and become a subscriber today. Enjoy unlimited access to local news and the latest on Leeds United, With a digital subscription, you see fewer ads, enjoy faster load times, and get access to exclusive newsletters and content. Click here to subscribe.