Hato Mayor is one of the 32 provinces of the Dominican Republic. It is part of the Eastern Region, next to the provinces of Monte Plata, La Romana, San Pedro de Macoris, El Seibo and La Altagracia. The provincial capital is the city of Hato Mayor del Rey, commonly known as Hato Mayor. It is one of the most recent provinces in the country. It was created on December 3,1984 by means of Law No.245 but it came into force on January 1,1992. Its first authorities were chosen in the elections of May 16,1992. The province was integrated by municipalities Hato Mayor del Rey, Sabana de la Mar and El Valle.
Hato Mayor was declared the first Ecotourism province of the Dominican Republic, through Law 77-02 of June 19,2002, since it contains valuable ecosystems for the preservation of the country's biodiversity.