The Mordvinic languages,^[3] also known as the Mordvin,^[4] Mordovian or Mordvinian languages (Russian: мордовские языки, mordovskiye yazyki),^[5] are a subgroup of the Uralic languages, comprising the closely related Erzya language and Moksha language, both spoken in Mordovia.^[6]

Previously considered a single "Mordvin language",^[7] it is now treated as a small language grouping.^[8] Due to differences in phonology, lexicon, and grammar, Erzya and Moksha are not mutually intelligible.^[9] The two Mordvinic languages also have separate literary forms. The Erzya literary language was created in 1922 and the Mokshan in 1923.^[10]

Phonological differences between the two languages include:^[7]

• Moksha retains a distinction between the vowels /ɛ, e/ while in Erzya, both have merged as /e/.
• In unstressed syllables, Erzya features vowel harmony like many other Uralic languages, using [e] in front-vocalic words and [o] in back-vocalic words. Moksha has a simple schwa [ə] in their place.
• Word-initially, Erzya has a postalveolar affricate /tʃ/ corresponding to a fricative /ʃ/ in Moksha.
• Next to voiceless consonants, liquids /r, rʲ, l, lʲ/ and the semivowel /j/ are devoiced in Moksha to [r̥ r̥ʲ l̥ l̥ʲ ȷ̊].

The medieval Meshcherian language may have been Mordvinic or close to Mordvinic^{[citation needed]}.

Traditionally, Uralicists grouped the Mordvinic and Mari languages together in the so-called Volgaic branch of the Uralic family; this view was however abandoned in the late 20th century.^[11] Instead, some Uralicists now prefer a rapid expansion model, with Mordvinic as one out of nine primary branches of Uralic; others propose a close relation between Mordvinic with the Finnic and Saamic branches of Uralic.^[12][13][14]