Grand Coteau is a town in St. Landry Parish, Louisiana, United States. The population was 1,040 at the 2000 census. Grand Coteau is on Interstate 49 south of Opelousas, Louisiana. The town is a center for local farming. As of 2004, the mayor is Jean Coco. Grand Coteau apartments for rent comparison page shows most up to date rent information on Grand Coteau apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.