Rourke played 11 games with the Islanders last season, registering an assist. The 27-year-old also collected 20 points (5-15) with Bridgeport of the AHL.
"We have added depth to our defence with the addition of Allan," Oilers vice-president of hockey operations Kevin Prendergast said in a release Thursday. "He is a veteran of seven pro seasons, and will provide us with experience in Springfield (Edmonton's AHL affiliate)."
The six-foot-one, 215-pound Mississauga, Ont., native has a goal and four assists in 42 career games with Carolina and the Islanders.