The Nuclear South Bird's Head, Core South Bird's Head or East South Bird's Head languages form a small language family of western New Guinea.
They either form part of a wider South Bird's Head language family, or may be an independent language family if not related to the Inanwatan and Konda–Yahadian languages.
[1] There are six languages:[2] Some lexical reconstructions by Usher (2020) are:[3]