Wintu (/wɪnˈtuː/ win-TOO) was a Wintuan language formerly spoken by the Wintu people of Northern California. It was the northernmost member of the Wintun family of languages. The Wintun family of languages was spoken in the Shasta County, Trinity County, Sacramento River Valley and in adjacent areas up to the Carquinez Strait of San Francisco Bay. Wintun is a branch of the hypothetical Penutian language phylum or stock of languages of western North America, more closely related to four other families of Penutian languages spoken in California: Maiduan, Miwokan, Yokuts, and Costanoan.

As of 2011, Headman Marc Franco of the Winnemem Wintu has been working with the Indigenous Language Institute on revitalization of the Winnemem Wintu language.

Wintu has 28 (to 30) consonants:

Wintu has 10 (or 11) vowels:

Segmental phonemes require obligatorily a single onset consonant. The rhyme is usually composed of a vowel nucleus of a long or a short vowel optionally followed by a single consonant. The syllabic canon is

Some examples of a generic syllable structure are:

Consonant clusters result only from conjoined closed syllables. For example, clusters of consonants occur when a syllable ending in a consonant is followed in the same word by another syllable. Some examples of consonant clusters are:

Vowels may be long, but sequences of vowels do not occur.