is a name used to refer to different indigenous ethnic groups in the Toluca Valley in the state of México, located in the central highlands of Mexico.
The term is applied to the ethnic group inhabiting the valley of Toluca and to their language, Matlatzinca.
The political capital of the valley was also referred to as “Matlatzinco”; this was a large city whose ruins are today known as the archaeological site of Calixtlahuaca.
In Prehispanic times the Toluca Valley was the home to speakers of at least four languages: Otomi, Matlatzinca, Mazahua, and Nahuatl.
Matlatzinca is severely endangered and now only spoken by around 100, mostly elderly people in San Francisco Oxtotilpa and Ocuiltec/Tlahuica spoken by between 50-100 in Ocuilan municipio in the villages San Juan Atzingo and Santa Lucía del Progreso.