|Region||State of Mexico|
|1,800 (2010 census)|
The Matlatzincan languages are two closely related Oto-Manguean language of the Oto-Pamean spoken in Central Mexico: Tlahuica/Ocuiltec and Matlatzinca. The name of the language in the language itself is pjiekak'joo.
The Matlatzincan language group consists of two mutually unintelligible languages: one called Ocuiltec or Tlahuica, the other called Matlatzinca proper. While originally one language they are now so removed that they are considered separate languages both by linguists and by the speakers themselves.
In 2000 Matlatzinca was spoken by around 650 persons in San Francisco Oxtotilpa, and in 2011 Ocuiltec/Tlahuica was spoken by around 100 persons in the municipality of Ocuilan de Arteaga in the villages San Juan Atzingo and Santa Lucía del Progreso.
Because of the extremely small population and the unfavourable age structure, the Matlatzincan languages are considered to be highly endangered. In the 2000 census, only 26 persons under the age of 20 were registered as speakers of Ocuiltec.
In 2003, together with 62 other languages, it was recognised as an official language of Mexico (per General Law of Linguistic Rights of the Indigenous Peoples) as an official language in the Mexican Federal District and the other administrative divisions in which it is spoken, and on an equal footing with Spanish.
- INALI (2012) México: Lenguas indígenas nacionales
- Hammarström, Harald; Forkel, Robert; Haspelmath, Martin, eds. (2017). "Matlatzincan". Glottolog 3.0. Jena, Germany: Max Planck Institute for the Science of Human History.
- Sabino Nava, Rocío. "¿ Somos Ocuiltecos, Atzincas, Tlahuicas o Pjiekakjo?." Estudios de Cultura Otopame 7, no. 1.
- Cazes, D. (1971). La lengua Maclasinca de Nsampaanchu, San Francisco Oxtotilpan. Journal de la Société des Américanistes, 60(1), 191-232.
- Muntzel, M. C. (2003). The structure of Ocuilteco. PhD Thesis, UMI, Ann Arbor.
- Hernández, R. E., & Hernández, M. (1999). Matlatzinca de San Francisco Oxtotilpan, Estado de México (Vol. 23). El Colegio de México.
- Palancar, Enrique L. 2016. Oto-Pamean. 
- The Ley General de Derechos Lingüísticos de los Pueblos Indígenas Archived 2007-02-08 at the Wayback Machine. ("General Law of the Linguistic Rights of Indigenous peoples"), decree published 13 March 2003