Cotulla is a city in and the county seat of La Salle County, Texas, United States. The population was 3,614 at the 2000 census. In 1868, Polish immigrant Joseph Cotulla arrived in La Salle County and eventually established a large ranching operation. After learning that the International-Great Northern Railroad intended to lay tracks in La Salle County, he worked to establish the town of Cotulla. In 1881, he donated 120 acres of his land to the railroad, and 1882, a depot was built there. In 1883, the town was granted a Post office. The same year, Cotulla became the county seat by special election.