Usulatan from the Nahuatl language (meaning "city of the ocelots") is a department of El Salvador in the southeast of the country (Lenca region). The capital is Usulután.
It is El Salvador's largest department. It has an area of 2,130 km² and a population of over 350,000.The department was created on June 22, 1865.
On October 26, 1948, the Alegria district was abolished and a new one called Santiago de Maria was created; it contains the cities of Santiago de Maria, which is the main city, as well as Alegria, Tecapan and California.
Usulutan City, the department's capital, was founded by the Lencas tribes but it was conquered by the Pipiles tribes. Some of the best beaches in El Salvador are located in Usulutan, and others such as El Espino are now under development.