Aransas County is a county located in the U.S. state of Texas. It is part of the Corpus Christi Metropolitan Statistical Area. As of the 2010 census, the population was 23,158. Aransas County was formed in 1871 from portions of Refugio County. It was named after Rio Nuestra Senora de Aranzazu, a Spanish outpost in early Texas.The first European to see this land was probably Alonso Álvarez de Pineda, who sailed along the coast of Texas in the summer of 1519 and who also discovered the Aransas Bay.