Wamesa is an Austronesian language of Indonesian New Guinea, spoken across the neck of the Doberai Peninsula or Bird's Head. There are currently 5,000–8,000 speakers.^{[citation needed]} While it was historically used as a lingua franca, it is currently considered an under-documented, endangered language. This means that fewer and fewer children have an active command of Wamesa. Instead, Papuan Malay has become increasingly dominant in the area.

The language is often called Wandamen in the literature; however, several speakers of the Windesi dialect have stated that Wandamen and Wondama refer to a dialect spoken around the Wondama Bay, studied by early missionaries and linguists from SIL. They affirm that the language as a whole is called Wamesa, the dialects of which are Windesi, Bintuni, and Wandamen. While Wamesa is spoken in West Papua, Wamesa is not a Papuan language but rather a South Halmahera–West New Guinea (SHWNG) language.

Locations:

There are five contrastive vowels in Wamesa, as is typical of Austronesian languages. These vowels are shown in the tables below.

Five diphthongs appear in Wamesa: /au/, /ai/, /ei/, /oi/, and /ui/. Two-vowel and three-vowel clusters are also common in Wamesa. Almost all VV-clusters contain at least one high vowel, and no two non-high vowels may be adjacent in larger clusters.

There are 14 consonants in Wamesa, three of which are marginal (shown in parentheses in the table below).

Labial, coronal and velar places of articulation are contrastive in Wamesa. Coronal plosives sound relatively dental and may therefore be referred to as alveolar or alveo-dental until palatography can be executed to corroborate this. Lateral /l/ and affricate /d͡ʒ/ appear only in loanwords, while all other sounds occur in native Wamesa words. The voiced velar fricative /g/ is a marginal phoneme because it only appears following /ŋ/.

The coronal tap and trill are in free variation, though the trill tends to occur more in word-initial or word-final position and in careful speech.