Petronila is a city in Nueces County, Texas, United States.

[4] According to the United States Census Bureau, the city has a total area of 1.8 square miles (4.7 km2), all land.

As of the 2020 United States census, there were 89 people, 37 households, and 20 families residing in the city.

There were 3.7% of families and 5.3% of the population living below the poverty line, including 9.1% of under eighteens and 6.7% of those over 64.

The City of Petronila is served by the Bishop Consolidated Independent School District.