The promotion hero, who is the club’s longest serving player having joined in 2014, will be at the AESSEAL New York Stadium until June 2023.
The experienced centre-half, who turns 37 next month, has been a key part of the set-up at the Millers, playing an integral role in linking the dressing room with Warne and his coaching staff.
Wood and his team-mates have recently returned from Las Vegas where they celebrated their return to the Championship.
It was the third promotion Wood has enjoyed at the Millers, famously scoring twice in a Wembley play-off final in 2018 and then captaining the side to a points-per-game promotion in 2020.
The fate of the rest of the out-of-contract players will be revealed soon, with some expected to leave the club while others will be offered new deals.