Dublin is a city located in southwestern Erath County in Central Texas. The population was 3,654 at the time of the 2010 census.The town is the former home of the world's oldest Dr Pepper bottling plant (see Dublin Dr Pepper). The plant was for many years the only U.S. source for Dr Pepper made with real cane sugar (from Texas-based Imperial Sugar), instead of less expensive high fructose corn syrup.