The fauna of Indonesia consists of a high level of biodiversity due to its vast-size and tropical archipelago make-up. Indonesia divides into two ecological regions; western Indonesia is more influenced by Asian fauna, and the east is more influenced by Australasian. The Wallace Line—in fact, more an area known as Wallacea—notionally divides these two regions. This unique blend of fauna in Indonesia is also affected by the diverse range of ecosystems, including beaches, sand dunes, estuaries, mangroves, coral reefs, sea grass beds, coastal mudflats, tidal flats, algal beds, and small island ecosystems.

Ecological issues have appeared in the nation due to the rapid industrialisation process and high population growth, resulting in lower priority level to preserve the ecosystems. The situation has worsened by illegal logging activity, in which resulting deforestation; while other problems, including high level of urbanisation, air pollution, garbage management and waste water services also contributing to the forest deterioration.