Petrolia is a town in southwestern Ontario, Canada. It is part of Lambton County and is surrounded by Enniskillen Township. It is billed as "Ca…Petrolia is a town in southwestern Ontario, Canada. It is part of Lambton County and is surrounded by Enniskillen Township. It is billed as "Canada's Victorian Oil Town" and is often credited with starting the oil industry in North America, a claim shared with the nearby town of Oil Springs.