The South Bougainville or East Bougainville languages are a small language family spoken on the island of Bougainville in Papua New Guinea.

They were classified as East Papuan languages by Stephen Wurm, but this does not now seem tenable, and was abandoned in Ethnologue (2009).

Glottolog v4.8 presents the following classification for the South Bougainville languages:[1] Terei Uisai Siwai Avaipa Simeku Naasioi Ounge Daantanaiʼ Koromira Sibe (Nasioi) Ross reconstructed three pronoun paradigms for proto-South Bougainville, free forms plus agentive and patientive (see morphosyntactic alignment) affixes: A detailed historical-comparative study of South Bougainville has been carried out by Evans (2009).

[2] Reconstructed Proto-South Bougainville lexicon from Evans (2009): South Bougainville words of likely Proto-Oceanic origin:[3] South Bougainville languages have SOV word order, unlike the SVO Oceanic languages.

[3]