Opelousas (French: Les Opélousas; Spanish: Los Opeluzás) is a small city in, and the parish seat of, St. Landry Parish, Louisiana, United States. Interstate 49 and U.S. Route 190 were constructed with a junction here. According to the 2020 census, Opelousas has a population of 15,547, and is currently declining at a rate of -1.16% annually and its population has decreased by -6.53% since the most recent census, which recorded a population of 16,634 in 2010. Opelousas is the principal city for the Opelousas-Eunice Micropolitan Statistical Area, which had an estimated population of 92,178 in 2008. Opelousas is also the fourth largest city in the Lafayette-Acadiana Combined Statistical Area, which has a population of 537,947.
With an area of 7.5 square miles, Opelousas is the most densely populated incorporated city in Louisiana.
Historically an area of settlement by French and Spanish Creoles, Creoles of color, and Acadians, Opelousas is the center of zydeco music. It celebrates its heritage at the Creoles of Color Heritage Folklife Center, one of the destinations on the new Louisiana African-American Heritage Trail. It is also the location of the Evangeline Downs Racetrack and Casino.
The city calls itself "the spice capital of the world", with production and sale of seasonings such as Tony Chachere's products, Targil Seasonings, Savoie's cajun meats and products, and LouAna Cooking Oil.