Petrolia is a city in Clay County, Texas, United States.

It is part of the Wichita Falls, Texas Metropolitan Statistical Area.

Texas State Highway 79 passes through the center of town, leading southwest 17 miles (27 km) to Wichita Falls and northeast 18 miles (29 km) to Waurika, Oklahoma.

Texas State Highway 148 leads south from the center of Petrolia 14 miles (23 km) to Henrietta, the Clay County seat.

According to the United States Census Bureau, Petrolia has a total area of 0.73 square miles (1.9 km2), all land.