Maybrat is a Papuan language spoken in the central parts of the Bird's Head Peninsula in the Indonesian province of Southwest Papua.

Maybrat is also known as Ayamaru, after the name of its principal dialect, while the divergent Karon Dori dialect has sometimes been counted as a separate language. Maybrat has not been demonstrated to be related to any other language, and so is often considered a language isolate. Nevertheless, in its grammatical structure, it has a number of features that are shared with the neighbouring languages.

Maybrat is characterised by a relatively small consonant inventory and an avoidance of most types of consonant clusters. There are two genders: masculine and unmarked. Verbs and inalienably possessed nouns alike take person prefixes. There is an elaborate system of demonstratives (words like "this" or "that"), with encoding for distance from the speaker, specificity, and syntactic function. In the clause, there is a fairly rigid subject–verb–object word order, and within noun phrases modifiers follow the head noun. Verb sequences, including serial verbs are very common, and verbs are used for a number of functions which in languages like English are served by adjectives or prepositions.

With around 25,000 speakers (as of 1987), Maybrat is among the most populous languages of Indonesian Papua. Its speakers are the Maybrat people, who mainly practice hunting, fishing, and swidden agriculture. They have traditionally lived in scattered homesteads, with the organisation into villages (kampongs) initiated by the efforts of the Dutch administration between the 1930s and the 1950s. These villages, like the establishment of the settlement of Ayawasi in 1953, brought together scattered local groups where each family had spoken a slightly different dialect, resulting in a "melting pot" where the small dialectal differences are less pronounced in the speech of the younger generations.

Maybrat is spoken in a large area in the central parts of the Bird's Head Peninsula, with a large portion of its speakers concentrated around the Ayamaru Lakes, although many are also found in urban areas of Indonesian Papua. Maybrat is surrounded by a number of languages; to the north are two other isolates: Abun and Mpur; to the east are Meyah and Moskona, both members of the East Bird's Head language family; the South Bird's Head languages Arandai, Kaburi, Kais, and Konda are spoken to the south, and to the west are Tehit and Moraid, both of the West Bird's Head family.

The Malay language served as the language of wider communication in this area during the Dutch administration, while more recently the related Indonesian language has taken up this role. Most Maybrat speakers in Ayawasi, for example, are fully bilingual in Indonesian, with the use of Indonesian loanwords and code-switching between the two languages fairly common.

The word "Maybrat" is a compound of mai 'sound, language', and according to one explanation, its meaning is "the language Brat", where "Brat" is the name of a hill near the village of Semetu in the Ayamaru region.

Maybrat is often considered to be a language isolate, as a relationship to any other language has not yet been established. There have been attempts to subsume it under putative families like the "Toror languages" (including Abun and the West Bird's Head languages), or the broader West Papuan family. Even if not demonstrably related to any other language and sharing only a small percentage of its vocabulary with its neighbours, Maybrat nevertheless has a great deal in its grammatical structure that resembles other languages of the Bird's Head.