Marble Falls is a city in Burnet County, Texas, United States. As of the 2016 United States Census, the city population was 7,154. It is about 58 miles (93 km) northwest of downtown Austin and 85 miles (137 km) north of San Antonio.
Lake Marble Falls is part of the Highland Lakes on the Colorado River, the largest chain of lakes in Texas. It hosts one of the largest drag boat races in the United States each August.