The player has triggered a clause in his contract which allows him to leave if he is accepting an offer from an NRL club. He has signed a two-year deal with the Australian club.
McCarthy is delighted to have been given the opportunity to test himself in the world’s premier competition, especially after playing for Northern Pride in the Queensland Cup before joining Rovers.
“It’s been a tough decision to make as I’ve really enjoyed playing for the club this season,” he told KR’s official website.
“There’s a great group of players here at the moment who make it enjoyable to come to training every day and it’s been a huge honour to lead them.
“Captaining such a proud and historic club like Hull KR in the Challenge Cup Final was one of the highlights of my career so far despite the result and I would have been very happy to stay at the club.
“It’s always been one of my ambitions to play in the NRL though and joining St George for next season was an opportunity that in the end I couldn’t afford to turn down.
“I loved my time in Australia last season and I’m looking forward to challenging myself against some of the best players in the world.
“However, I’ve got a job to do here first and I’ll be doing my very best to finish the year strongly with Hull KR. We’ve put ourselves in a good position in the Super 8s and we need to kick on and end the season on a high.
“That’s the least we owe to the fans who have been great with me ever since I came to the club. I’d heard good things before I arrived but they’ve surpassed all expectations and I can’t thank them enough for everything they have done for me and the boys.”
McCarthy, 27, has played 72 first-grade games with Hull KR and Warrington, and won two Challenge Cup finals with the Wolves in 2009 and 2012.
“Tyrone is a versatile player who has shown a keen interest in testing himself at the highest level in the NRL competition,” Dragons director of recruitment and retention Peter Mulholland told his club’s official website.
“He has established himself in the Super League competition and has a sound understanding of what is required to compete in the NRL from his time playing for the Northern Pride in the Queensland Cup.
“We look forward to welcoming him to the Club during the off-season.”