Wood, who was already contracted for 2018, has signed on until the end of 2020. He was due to become a free agent at the end of next season.
The 27-year-old has played a total of 122 games since debuting in Round 19,2009.
List manager Jason McCartney said the club is thrilled to secure the signature of one of the club’s most important players.
“I can’t speak highly enough of Easton as a player and as an individual,” McCartney said.
“On the field he’s athleticism and intercept marking abilities are elite and he rarely gets beaten in a one-on-one contest.
“And off the field, he’s obviously a key member of our group. He had big shoes to fill last season, stepping in as captain for Rob Murphy, and he couldn’t have handled it better.
”He loves the Club, and we’re really pleased he’s chosen to extend his contract this early.”
Wood was recruited by the Dogs with pick No.43 in the 2007 National Draft.