Luling /ˈluːlɪŋ/ is a city in Caldwell and Guadalupe counties, Texas, United States, along the San Marcos River. The population, as of the 2010 census, was 5,411, and the population was estimated at 5,764 in 2015. The town was named after a New York banker, Charles Luling. He was a personal friend of Thomas Wentworth Pierce, and provided the financing for the railroad as well the purchase of the land that became Luling. The Caldwell County portion of Luling is part of the Austin metropolitan area.