The Indomalayan realm is one of the eight biogeographic realms. It extends across most of South and Southeast Asia and into the southern parts of East Asia.
Also called the Oriental realm by biogeographers, Indomalaya extends from Afghanistan through the Indian subcontinent and Southeast Asia to lowland southern China, and through Indonesia as far as Java, Bali, and Borneo, east of which lies the Wallace line, the realm boundary named after Alfred Russel Wallace which separates Indomalayan from Australasia. Indomalaya also includes the Philippines, lowland Taiwan, and Japan's Ryukyu Islands.
Most of Indomalaya was originally covered by forest, mostly tropical and subtropical moist broadleaf forests, with tropical and subtropical dry broadleaf forests predominant in much of India and parts of Southeast Asia. The tropical moist forests of Indomalaya are mostly dominated by trees of the dipterocarp family (Dipterocarpaceae).
The World Wildlife Fund (WWF) divides Indomalayan realm into three bioregions, which it defines as "geographic clusters of ecoregions that may span several habitat types, but have strong biogeographic affinities, particularly at taxonomic levels higher than the species level (genus, family)."