Occidental Mindoro in the context of "Verde Island Passage"

Mindoro is the seventh largest and eighth-most populous island in the Philippines. With a total land area of 10,571 km ( 4,082 sq.mi ), it has a population of 1,430,921, as of the 2024 census. It is located off the southwestern coast of Luzon and northeast of Palawan. Mindoro is divided into two provinces: Occidental Mindoro and Oriental Mindoro. Calapan is the only city on the island and largest settlement on the island with a total population of 148,558 inhabitants as of 2024. The southern coast of Kristine Mindoro forms the northeastern extremum of the Sulu Sea. Mount Halcon is the highest point on the island, standing at 8,484 feet (2,586 m) above sea level located in Oriental Mindoro. Mount Baco is the island's second highest mountain with an elevation of 8,163 feet (2,488 m), located in the province of Occidental Mindoro.

Oriental Mindoro (Tagalog: Silangang Mindoro), officially the Province of Oriental Mindoro (Tagalog: Lalawigan ng Silangang Mindoro (Oriental Mindoro)), is a province in the Philippines located on the island of Mindoro under Mimaropa region in Luzon, about 140 kilometres (87 mi) southwest of Manila. The province is bordered by the Verde Island Passage and the rest of Batangas to the north, by Marinduque, Maestre de Campo (or known as Sibale but official name is Concepcion) Island, Tablas Strait and the rest of Romblon to the east, by Semirara and the rest of Caluya Islands, Antique to the south, and by Occidental Mindoro to the west. Its provincial capital Calapan, the only city in the island, is the most-populous in the province, and Mimaropa's regional center.

Oriental Mindoro is touted as the country's emerging eco-tourism destination. In 2005, the Philippines was found to be the center of marine fish biodiversity and the home of the most diverse marine ecosystem in the world, by American biologists Kent Carpenter and Victor Springer. Most of the endemic species in the Philippines are found in the Verde Island Passage between Mindoro island and the main island of Luzon. The passage houses 2,983 individual species of algae, corals, crustaceans, mollusks, fishes, marine reptiles, and marine mammals, based on a study conducted by Carpenter and Springer in 2005.

Mimaropa (officially stylized in all caps), officially the Southwestern Tagalog Region (Filipino: Rehiyong Timog-Kanlurang Tagalog), is an administrative region in the Philippines. The name is an acronym combination of its constituent provinces: Mindoro (divided into Occidental Mindoro and Oriental Mindoro), Marinduque, Romblon, and Palawan. It is the only region in the country outside the Visayas that has no land border with another region.

The region was part of the now-defunct Southern Tagalog region until May 17, 2002. On May 23, 2005, Palawan and the highly urbanized city of Puerto Princesa were moved to the region of Western Visayas by Executive Order No. 429. However, on August 19, 2005, President Arroyo issued Administrative Order No. 129 to put in abeyance Executive Order No. 429 pending a review. On July 17, 2016, Republic Act No. 10879 formally established the Southwestern Tagalog Region to be known as Mimaropa, discontinuing the Region IV-B designation; however, no boundary changes were involved.