San Luis de la Reina is a municipality in the San Miguel department of El Salvador. San Luis is an ecotourist destination. In the late 18th century, the Ostucal Hacienda was owned by the parish of Osicala. It produced indigo, cereals, and raised cattle. In 1811, it was constructed into and raised to a city; patronal festivals are held on 24 and 25 August.