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.
It's a tribute to him, and everything he's done and deserved is coming to fruition tonight with his jersey in the rafters. He's going to be a first-ballot Hall of Famer. And I said today, if he's not, take my stuff out. If he doesn't deserve to be in there first ballot, no one does. Except for (Wayne) Gretzky, I guess.
— Hockey Hall of Fame member Brett Hull on former teammate Mike Modano, whose No. 9 was retired by the Dallas Stars on Saturday