The new contract will see Tumeth progress directly into the Tigers' top 30 for 2023, having been sat on a development contract throughout the 2022 season.
Tumeth represented New South Wales in the under-19 State of Origin match this year while on his development deal, and at 19, has already been part of the club's NSW Cup side, having previously worked his way through the Balmain SG Ball and Jersey Flegg systems.
He played his junior football for the Concord-Burwood Wolves and is regarded as one of the better young second-rowers in the game with a nice turn of footwork and ability to ball play.
Tumeth has been officially contracted to the Tigers since he was a 15-year-old, and while he is yet to make his NRL debut, it's likely that will occur this year.
He said he was excited to extend his stay.
“I've been with the club for a few years now and I love the place. My teammates, the staff, the fans, our new facility, everything about the club is great.
I'm over the moon to have signed a new deal as part of the top squad and I can't wait to get stuck into pre-season training.”
Incoming coach Tim Sheens said the signing of Tumeth was evidence of how the club's junior pathways are working.
"It's tremendous to see a young man come through the junior rep teams and get to where is now," the coach said.
"It's a great example to other juniors in our system of what is possible with hard work and patience.
“We all look forward to being a part of Brandon's continued development over the coming years."