The rookie was already contracted for both this season and next under his existing deal, which has now been updated.
The extension covers multiple years beyond 2025 which means he will likely stay with the team until at least the end of the 2027 Supercars season.
Wood said agreeing to a longer-term deal was an easy decision.
“It’s so awesome to be able to extend with the team, there’s nowhere else I’d rather be, and it’s really nice to know it’s all locked away, and my focus can be on racing and developing,” he said.
“It was a pretty easy decision to be honest; from the moment I walked in here it felt like home, and it’s a really cool feeling to have that same support and trust back from everyone here. The word family gets thrown around a lot, but it’s the perfect way to describe how we operate.
“I think we are building something special here at Walkinshaw Andretti United, and I’m really excited to see what we can do in the next few years together. I’m looking forward to repaying the faith everyone has shown me from the start.”
WAU co-owner Ryan Walkinshaw said the early renewal was a simple case of ‘why not?’.
“We are really excited to share the news that we’ve locked in our future with Ryan,” he said.
“It wasn’t a tough decision for any of us. We had another year left on Ryan’s existing contract, but we are extremely confident of the future we have together. There wasn’t any reason not to get it locked away as soon as possible.
“He’s already showed results far beyond his experience in his first six months in the category, sometimes we have to remind ourselves of just how young he is, and how early into his racing career he is.
“Not only is he an outstanding talent on track with an incredibly bright future, but he is fantastic for our team culturally as well – we love having him here. We can’t wait to see him alongside Chaz long into the future.”