Vowel hiatus is a prohibited configuration of vowels in many languages of the world. This study is established to examine strategies used to resolve vowel hiatus in Olusuba, a Bantu language spoken in parts of Kenya, Tanzania and Uganda, within the framework of Optimality Theory (OT). The work describes two vowel processes used as hiatus resolution strategies in Olusuba. Well-formedness of data obtained in this study are analysed using OT. The theory explains how constraints interact to optimise the output in this language. Using descriptive analytic research design and following the available data obtained from native speakers of Olusuba, this paper provides two vowel processes used as strategies in resolving a sequence of dissimilar vowels in the language under study.