Llano is a city in and the county seat of Llano County, Texas, United States. As of 2020, the city population was 3,325. Llano has been de…Llano is a city in and the county seat of Llano County, Texas, United States. As of 2020, the city population was 3,325. Llano has been described as the "deer capital of Texas", with the single highest density of white-tailed deer in the United States.