The deal ties Wallis to the Kennel to at least the end of the 2018 season.
Wallis has enjoyed a career best season under new coach Luke Beveridge, averaging 22 disposals per game.
“It was always going to happen it was just a matter of time,” Wallis told the club website.
“I can’t be more excited and I can’t wait for the next game, but the next few years to start at the Bulldogs.”
Read more at WesternBulldogs.com.au