On the verge of State of Origin selection this year after being named as the 18th man for Game 1 before pulling out due to injury, Graham has fast become one of the best and most consistent performers in the competition.
A three-year extension to go with next year that he was already contracted for means Graham has re-signed to remain at Redfern until 2027.
At just 24 years of age, Graham will likely only keep improving and there was set to be a wild race for his services from November 1, with questions looming over South Sydney's salary cap and positions on the park following the signing of Jack Wighton from the start of 2024.
The signing of Graham - who will be on an upgrade - will undoubtedly leave the Rabbitohs with contract questions to answer over a host of off-contract players at the end of next year, including Jai Arrow, Thomas Burgess, Peter Mamouzelos, Shaquai Mitchell, Isaiah Taass and Origin debutant Keaon Koloamtangi.
Despite that, the Rabbitohs had no hesitation in locking up Graham before November 1, with head of football Mark Ellison said his contract was a "priority."
"Campbell has proven himself to be one of the leading centres in the game," Ellison said in a statement released by the club.
"He has risen through the grades at South Sydney to play first grade at just 18 years of age, and since that day at the SCG he hasn't looked back.
"He has represented his Country and was unlucky not to represent his State this year, but we know he will get the opportunity to represent New South Wales in the years to come because of the quality of player and teammate that he is.
"He is a South Sydney man through and through and we want to achieve our Club's goals with him and his family playing a key role in that success. We all love working with 'Stretch' and we look forward to continuing that work with him over the seasons to come."
Graham said the decision to remain at the Rabbitohs was an easy one.
"I'm very excited to know that my future for the next four years is going to be here at Souths," Graham said.
"This Club really is my home and I've always felt that way. I love this Club, I love everybody involved with this Club, I feel so at home here, so it wasn't a hard decision for me to stay here and work towards winning some Premierships here over the next few years.
"I'm very grateful to the Club for putting their faith in me and wanting to have me here at the Club. I'm looking to pay them back with my performances for the rest of this season and the next few years as well.
"Over the last few seasons, I've built some great relationships amongst the players and coaching staff. We've had a group of young lads coming through and I can't wait to see all of the new talent coming through to join some of the tried-and-true performers we have in our squad.
"Our Members have also shown me so much support. I get so much love from the Members and fans. The support is so good, I feel so loved at this Club, and we have the best Members in the game. I'm so grateful that I will get to hear them cheer me on for the next four years."