Off-contract at the end of 2019, the reigning Dragons Player of the Year recipient will now remain at the club until at least the end of the 2022 NRL season.
The 26 year old played all but one NRL game for the Dragons this season and made his long-awaited State of Origin debut for New South Wales in Game Three.
Sims was pleased to be remain at the club, where he has been since midway through the Dragons’ 2016 campaign.
Director of Rugby League Pathways and List Management Ian Millward said Sims’s retention was crucial in helping the Dragons maintain one of the best forward packs in the NRL.
Other Fiji Bati stars that will feature for the Dragons next year includes Korbin Sims, Mikaele Ravalawa and Joe Lovodua.