Originally signed until the end of 2021, the new deal will tie the 22-year old to Redfern until at least the end of the 2025 season.
Murray has played 62 NRL appearances after making his debut in Round 8 of the 2017 season against the Brisbane Broncos.
The lock was thrilled to commit his future to the club.
“It’s very exciting for me and a great relief to have a large chunk of my future sorted now, and to know it will be at this Club that I love is very special for me and my family,” Murray told rabbitohs.com.au.
“I count my lucky stars at how everything has fallen into place and I have no intention of letting this go or slackening off. It means way too much to me, to play for this Club and to represent it every day.
“For almost the next six years at least I will be a Rabbitoh and the journey is really only just starting for me.
“It’s very exciting and I can’t wait to represent our Members on the field once again, starting this Friday night against the Roosters.”
Rabbitohs Head of Football Mark Ellison added: “I’ve watched Cameron play since he was five years of age. He never ceases to amaze me.
“He comes from a great family, has strong values, is already working on his life after football and is very focussed on being the best person, as well as footballer, that he can be every day.
“He has worked very hard to get to the position he is in now and the next challenge for him is to become the leader we all know he can be, as well as to cement himself in the New South Wales and Australian representative sides.
“We’re very happy to have finalised Cameron’s contract extension, as I am sure our Members and supporters are as well.”