Mambai, also called Mambae or Manbae, is a language spoken by the Mambai people, the second largest ethnic group in the island country of East Timor.

Mambai is one of 15 constitutionally recognized national languages.

The majority of the Timorese community in Australia is native in Mambai.

Mambai used to be spoken in the area around Dili, when the Portuguese declared the city to be the capital of their colony Portuguese Timor.

Therefore, the Tetum Prasa spoken in Dili is still exhibiting strong influences from its Mambai substrate.