Buol (Bual, Bwo’ol, Bwool, Dia) is an Austronesian language spoken in northwestern Sulawesi, Indonesia.

The vowels of Buol are /a e i o u/.^[2] Stress falls on penultimate syllable, with sequence of like vowels counting as one syllable.

The consonants are as follows:

/dʒ/ occurs in loans. /h/, /s/, /ʔ/ are found in loans and a small number of native words, such as /buahaŋa/ 'k.o. cricket', /sio/ 'nine', /naʔal/ 'bark slippers'.

/β/ only occurs before /u/, but there are near-minimal pairs such as /βuŋo/ 'fruit', /buŋol/ 'leaf'.

/l/ is pronounced [l] after a front vowel, as in [dila] 'tongue'; [ɽ] if not preceded, but followed by a front vowel, as in [aɽe] 'chin'; and [ʎ] elsewhere. However, there is an exception with the sequences /lala, lola, lolo/, where the first /l/ is pronounced [l], as in /lolo/ [loʎo] 'face'.