Santa María del Rosario is a town and

municipality A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term ''municipality'' may also mean the go ...

Oaxaca Oaxaca ( , also , , from nci, Huāxyacac ), officially the Free and Sovereign State of Oaxaca ( es, Estado Libre y Soberano de Oaxaca), is one of the 32 states that compose the political divisions of Mexico, Federative Entities of Mexico. It is ...

in south-western

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. The municipality covers an area of km². It is part of the

Tlaxiaco District Tlaxiaco District is located in the south of the Mixteca Region of the State of Oaxaca, Mexico. The main city is the Heroic City of Tlaxiaco Municipalities The district includes the following municipalities: * Chalcatongo de Hidalgo * Magdale ...

in the south of the

Mixteca Region The Mixteca Region is a region in the state of Oaxaca, Mexico, part of the broader La Mixteca area which covers parts of the states of Puebla, Guerrero and Oaxaca. The region includes the districts of Juxtlahuaca, Silacayoapam, Huajuapan, Coixtlah ...

. As of the 2010 census, the town (locality) had a population of 55 inhabitants, while the municipality for which it serves as municipal seat (''cabecera municipal'') had a total population of 480 inhabitants.2010 census tables: INEGI
Although the municipality is far from the least populous in Mexico (there are dozens of smaller ones in its own State of Oaxaca, and three others in the State of Sonora), its municipal seat is the smallest in all of Mexico. It is the only urban locality in the municipality.

References

Municipalities of Oaxaca {{Oaxaca-geo-stub