Opelousas is a small city located in St. Landry Parish, Louisiana, in the United States. It serves as the parish seat and functions as the principal city for the Opelousas-Eunice Micropolitan Statistical Area. The city is also identified as the fourth largest city within the Lafayette-Acadiana Combined Statistical Area.
The city features a junction where Interstate 49 and U.S. Route 190 intersect. According to the 2020 census, Opelousas had a population of 15,786, reflecting a 6.53 percent decline from its 2010 population of 16,634. The U.S. Census Bureau estimated the city's population to be 15,098 in 2025.