Mustang Ridge is a city in Caldwell, Bastrop, and Travis Counties in the U.S. state of Texas.

According to the United States Census Bureau, the city has a total area of 3.8 square miles (9.8 km2), all land.

Alton Brooks Laws was elected the first mayor, municipal judge, and state magistrate.

The Travis County portion of Mustang Ridge is served by the Del Valle Independent School District.

The Caldwell County portion is served by the Lockhart Independent School District.

When the police force is not working, the city is served by the sheriff's offices of Caldwell and Travis Counties.