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.
Obviously a lot happened in a short period of time. At the end of the day, considering everything I went through, I really felt close to my teammates and I really feel like what we accomplished, I know we didn't win it all. ... I'm really proud of how we got there and what we did once we got there.
— Rangers forward Martin St. Louis to Jim Cerny of BlueshirtsUnited.com