Jonestown, TX. Jonestown is a city in Travis County, Texas, United States. The population was 1,681 at the 2000 census. Jonestown is located at 30°29′20″N 97°55′27″W / 30.488872°N 97.924208°W / 30.488872; -97.924208 (30.488872, -97.924208). This is at the north end of Lake Travis, 19 miles (31 km) northwest of Austin.