Chinantla, or La Chinantla, is a culturally defined region in the Mexican state of Oaxaca, inhabited by the Chinantec people. Located in the Sierra Norte de Oaxaca, the region is mountainous and one of the wettest regions in Mexico. It has a high biodiversity, and the Chinantec people are noted for their efforts to protect the environment of the region.

"Chinantla" is derived from the Nahuatl chinamitl ("enclosed space"). The 1572 Relacion de Chinantla applied the name to an occupied town in Oaxaca, a nearby abandoned town, the surrounding region that included 28 dependent villages, and a river (now the Rio Valle Nacional) that flowed through that region. The name may have referred to the town and region being surrounded by mountains. Another interpretation is that the name referred to a palisade surrounding a village, and was a generic term for a village.

"Chinantla" refers to a area in Oaxaca inhabited by the Chinantec people. It includes most of the Tuxtepec District, the northern half of Choapam District, the northeast part of Villa Alta District, the northeast part of Ixtlán District, and the eastern part of Cuicatlán District, lying between 17°22' and 18°12' North and 95°43' and 96°38' West, with an area of about 20,000 square kilometres (7,700 sq mi). Botanists in the 19th century, as well as some in the 20th century, used "Chinantla" to refer to a restricted part of that region, including only northwestern Choapam, southernmost Tuxtepec, and northeastern Villa Alta districts in Oaxaca.

The Sierra Madre de Oaxaca, or Sierra Norte de Oaxaca, is part of the Sierra Madre del Sur. The Sierra Norte de Oaxaca runs northwest to southeast, blocking the high-humidity easterlies blowing across Mexico from the Gulf of Mexico. Most of the moisture in the easterlies is forced out by orographic precipitation on the windward (eastern) slopes of the mountains as the air moves over the mountains, bringing the highest rainfall in Mexico to the Chinanlta and creating a hyper-humid climate.

Chinantla includes parts of the Sierra Madre de Oaxaca and is part of the Papaloapan River basin. The region is humid with an annual rainfall between 3,600 and 5,800 millimetres (140 and 230 in). Average annual temperature is 25 °C (77 °F) in the Lowlands and 16 °C (61 °F) in the mountains. Eighty percent of the region has slopes between 6° and 45°. It includes a variety of climatic, geomorphologic, and edaphic conditions, overlaid on a complex geological history. The Sierra Madre de Oaxaca consists of upthrust limestone with igneous intrusions. Elevations above sea level range from 300 feet (91 m) to more than 9,000 feet (2,700 m), with most of the region between 900 and 3,720 feet (270 and 1,130 m)

The Chinantla has been called the "most exotic phytogeographic unit in Mexico". It includes one of the largest areas of tropical rainforest in Mexico. It also includes large areas of montane cloud forest and high-altitude pine–oak forests.

The Chinantecs have inhabited Chinantla since pre-Columbian times. At the time of the Spanish conquest of the Aztec Empire, Chinantla was a cultural and political region to the southwest of the Aztec garrison and administrative center of Tuxtepec in what is now northern Oaxaca. Little information on Chinantla from before the Spanish conquest has survived. A preserved Aztec manuscript mentions a military camapign by the Aztecs against Chinantla in 1479. The Aztec ruler Ahuitzotl conquered the Chinantecs in 1488. The Chinantecs joined Hernán Cortés in attacking the Aztec Empire in 1519. They were noted for the unusually long lances they fought with.

Chinantecs still use the milpa system of agriculture. The land is communally owned, but fields are assigned to families to cultivate. Maize and beans are the primary crops. Plants such as cucurbits and chayote are grown in the vicinity of dwellings, but other crops, primarily greens, are grown in the fields between the corn rows. The Chinantec have maintained their pre-Columbian tradition of sabio-curanderos ("herb doctors").