Grand Coteau is a town in St. Landry Parish, Louisiana, United States. The population was 947 at the 2010 census. Grand Coteau is on Interstate 49 south of Opelousas and is part of the Opelousas–Eunice Micropolitan Statistical Area. The town is a center for local farming. As of 2018, the mayor is Patrick Richard.
The first known land grant by the colonial Louisiana government was in 1776 in the area referred to as Buzzard Prairie. In the early 19th century, Buzzard Prairie served as a stopping point for travelers between Washington, Louisiana, and St. Martinville, Louisiana. The thriving community had two bakeries, a cobbler, a millinery, a blacksmith shop, a post office, six bars, and nine brothels.