Quintana Roo, officially Free and Sovereign State of Quintana Roo, is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 10 municipalities and its capital city is Chetumal.

It is located in Southeastern Mexico, on the eastern part of the Yucatán Peninsula. It is bordered by the states of Yucatán to the northwest and Campeche to the west. To the north, Quintana Roo borders the Gulf of Mexico and to the south, Belize. It also claims territory which gives it a small border with Guatemala in the southwest of the state, although this disputed area is also claimed by Campeche.

Quintana Roo is home of the world famous city of Cancún, the islands of Cozumel and Isla Mujeres, the towns of Bacalar, Playa del Carmen and Akumal, as well as the ancient Maya ruins of Chacchoben, Coba, Kohunlich, Muyil, Tulum, Xel-Há, and Xcaret. The Sian Ka'an Biosphere Reserve is also in the state.

The state officially covers an area of 44,705 square kilometers, but since 1997 there is a boundary dispute with the states of Yucatán and Campeche over an area of approximately 10,200 square kilometers.

The Yucatán Peninsula is one of the most forested areas of the world in terms of biotic mass per hectare.

 There are four generalized ecosystems in Quintana Roo.- tropical forests, or jungle, savanna, mangrove forests, and coral reefs. One of the byproducts of traditional and large-scale agriculture is the creation of additional habitats, such as second growth forests and fields.

 Also affected by the loss of habitat due to both agriculture and development, birds are one of the region's most varied animal assets. Hundreds of species reside in Quintana Roo permanently, with hundreds of others either wintering there or using it as a stopover on the long journey into South America. As a result, many birders come to the area annually in search of the rare and unexpected.