In 1857, James Miller Williams of Hamilton began distilling some of the "tar" lying around Oil Springs (located a few kilometers south from Petrolia), after buying the property rights from Charles Nelson Tripp.

In 2008, the 150th anniversary of the discovery, Canada Post issued a stamp commemorating this first commercial oil well, featuring portraits of Charles Tripp and Williams.

[3] However, these early wells resulted in a large amount of wastage from gushers, estimated at 5 million barrels (790,000 m3) of oil in 1862 alone.

The place separated from Enniskillen Township and was incorporated as a town on 25 December of that same year.

[7] Oil men from Petrolia travelled to the far reaches of the world (Gobi Desert, Arctic, Iran, Indonesia, United States, Australia, Russia, and over 80 other countries) teaching others how to find and extract crude oil.

Those born and raised in Petrolia are referred to as "Hard Oilers", paying tribute to the toughness of their ancestors.