Wolio is an Austronesian language spoken in Bau-Bau on Buton Island, Southeast Sulawesi, Indonesia. Also known as Buton, it is a trade language and the former court language of the Sultan at Baubau. Today it is an official regional language; street signs are written in Wolio using the Arabic script.
Stress is on the penultimate syllable. The five vowels are /i e a o u/.