Menai Bay is located on the southwestern coast of Unguja island (Zanzibar Island), in the Zanzibar Archipelago in Tanzania.
It is a 8 km wide bay on the Zanzibar Strait of the Western Indian Ocean.
The long coastline of Menai Bay has nineteen villages, with a total population of around 17,000. The villages are within the Unguja South Region of Zanzibar.
The Menai Bay Conservation Area is a marine reserve protecting the habitats and biota of the bay area.