Soyaltepec Mazatec is a Mazatecan language spoken in the Mexican state of Oaxaca, notably in the towns of Santa María Jacatepec and San Miguel Soyaltepec, and on Soyaltepec Island.

Due to flooding from the construction of a dam, the Soyaltepec-speaking area has had an influx of speakers of other Mazatecan languages. Perhaps only 900 people, mostly monolingual, still speak the original variety of Soyaltepec.

See Mazatecan languages for a detailed description of these languages.

The Soyaltepec Mazatec dialect contains five vowel sounds and nasals:

Glottal-sonorant consonants: /hm, hn, hɲ, ʔm, ʔn, ʔɲ, ʔw, ʔj/

Nasal-obstruent consonants: /nt, ŋk, nt͡s, nt͡ʃ/