Vitu (also spelled Witu or Vittu, referred by their own speakers as pole matotota 'true speech' or pole Vitu 'Vitu speech') or Muduapa is an Oceanic language spoken by about 7,000 people on the islands northwest of the coast of West New Britain in Papua New Guinea.

The name Vitu is an endonym. The alternative name, Muduapa, is an exonym from the neighboring Uneapa (or Bali) language spoken on Bali Island, which is in Vitu known as Mudua, referring to an island northwest of Vitu proper. Mudua and Muduapa can come from a proto-form *Muduap, reflecting the addition of an echo vowel in Bali and the regular loss of final consonants in Vitu.

Vitu and Bali form a subgroup within the Meso-Melanesian cluster of the Oceanic languages. Vitu is so closely related to the neighbouring Uneapa (or Bali) language that the two are sometimes considered to be a single language, called Bali-Vitu. However, there are some differences, particularly in their phonemic inventories, retention of final consonants (which is lost in Vitu), pronoun systems, and word choices. In general, Bali tends to be more conservative than Vitu in most respects.

Vitu is written in the Latin script. Only between 15% and 25% of speakers of Vitu are literate in the language, but many more are literate in Tok Pisin, the national language of Papua New Guinea.