The 38-year-old native of Regina moves into the position after a 17-year playing career.
"We are very excited to have Mike fill such an important role with us," said Oilers GM Steve Tambellini. "We know his experience of 1,000-plus NHL games will benefit our younger players and the development of their careers."
Sillinger has played for 12 NHL teams, most recently suiting up for the New York Islanders last season.
He's a special guy. Obviously we are lucky to have him. Just his talent, I'm not surprised anymore. You get to see this guy every practice, and you know what he's able to do. Obviously, it's pretty special for a guy that young to score a hat trick in playoffs, this type of a game too. Really happy for him.
— Predators goalie Pekka Rinne on Filip Forsberg, whose hat trick led Nashville to a Game 5 win vs. Chicago on Thursday