It's the first time Westlake, a 27-year-old from Oakville, Ont., will be captain at the Paralympics.
He's been the team's captain since the 2010-11 season, leading Canada to gold at the 2013 world championship and bronze at the worlds in 2011.
Brad Bowden of Orton, Ont., and Adam Dixon of Midland, Ont., will serve as alternate captains.
"This is the leadership team we have had in place since 2011, and we have the utmost confidence in them leading our team into Sochi," said head coach Mike Mondin.
"Greg, Brad and Adam have worn the Team Canada jersey with pride every time they have put it on, and have earned the right to wear a letter on the game's biggest stage."
Westlake previously won gold with the team at the 2006 Games in Turin, Italy before Canada missed the podium with a fourth-place result four years ago in Vancouver.
A member of the team since 2003, Westlake is second in all-time team scoring with 250 points (126 goals, 124 assists) in 147 games.