Ainaro, officially Ainaro Administrative Post (, ), is an administrative post (and was formerly a subdistrict) in Ainaro municipality, Timor-Leste. Its seat or administrative centre is the suco of Ainaro.
The administrative post has a population of approximately 14,130 people (2001). It contains the small mountain town of Ainaro, which is also the capital of the municipality, along with the sucos of Ainaro, Soro, Maununo, Cassa, Suro Craic, Manutassi, and Mau-Ulo.