The Koiarian languages are a small family of Trans–New Guinea languages spoken in the "Bird's Tail" (southeastern peninsula) of New Guinea. They are sometimes included in a speculative Southeast Papuan

Southeast Papuan languages

The Southeast Papuan or "Bird's Tail" languages are a geographic grouping of half a dozen small families of Papuan languages in the "Bird's Tail" of New Guinea: Koiarian, Kwalean, Manubaran, Yareban, Mailuan, and Dagan...

 branch of Trans–New Guinea (TNG), but the Southeast Papuan families have not been shown to be any more closely related to each other than they are to other TNG families.

The languages are:

• Koiaric branch: Grass Koiari, Mountain Koiari, Koitabu
• Baraic branch: Barai, Ese
  Ese language
  Ese is a language of Papua New Guinea. Dialects are Muaturaina, Chimona, Dea, Akabafa, Nami, Mesari, Averi, Afore, Minjori, Oko, Wakue, Numba, Jimuni, Karira. 40% of speakers are monolingual....
  
   (Managalasi), Namiae, Ömie