The former Hunlset Warriors amateur should now stay at Headingley until at least the end of the 2017 season.
During his Leeds career, Sutcliffe has made 44 first team appearances, and scored 11 tries in his 26 games in 2014.
“As soon as Gary Hetherington said the club would like to offer me a longer deal, I was more than happy to sign,” said Sutcliffe.
“I grew up dreaming of playing for the Rhinos and there is no other club I want to play for.
“Last season was great for me because of the amount of game time I was able to get and that has given me a lot of confidence going into next season.
“Pre-season has been great so far, especially because we have got so many players in for the whole build up. Training alongside all our experience players gives me and all the young lads a great boost and drives us on.
“I heard the comments Gary Hetherington made about building a squad for the future around our young players and that does give us a boost.
“The squad will have a period of transition over the next few years and for all the squad to know the vision for us as a group is both reassuring and acts as motivation for us to carry on the great tradition of success over the last decade.
“I know that 2015 is a big year for me to cement my place in the squad and I am doing everything I can in pre-season to make sure I make the most of the opportunity.”
Leeds head coach Brian McDermott is delighted that such a talented youngster has committed to the club.
“Liam has already shown he has all the qualities needed to succeed at the Super League level,” he said.
“Like a number of our young players, people forget how young he still is because he has been around the first team for a number of years.
“He is still developing his natural game but we saw last year that the foundations are definitely there.
“When you think back to his nerveless kick to win the game against Catalan in the summer it shows that he has a bright future in the game.”