The centre, who was drafted by the AFC East side in 2009, had been heading into the final year of his rookie deal, but has pledged his long-term future to the franchise.
The 27-year-old told the team's website: "First-class organisation all the way around and I couldn't be happier to be a part of it for the long term. I wouldn't have re-signed if I wasn't extremely excited about where we're going.
"Have a ton of faith in our front office right now that we're going in the right direction and I think it's going to start soon. Extremely excited about this season. Extremely excited to fill [Ralph Wilson Stadium] next week with all the fans for New England. It's going to be an electric atmosphere and I'm looking forward to it.
"I want to thank the community who has been so welcoming to me and my family since the day that I got here. The fans, everybody, have been great."
Wood has started 47 games in his four seasons with the Bills.