Insulindia is a somewhat archaic geographical term for Maritime Southeast Asia, equivalent in usage to Australasia and Indochina, and encompassing the entire area situated between the two. More common in Portuguese and Spanish, it is also sometimes used in art history or anthropology to describe the interface zone between the cultures Oceania and Southeast Asia.

Insulindia is used as a geopolitical term in academic discussions of the former European colonial possessions within the Maritime Southeast Asia, especially the Dutch East Indies and Portuguese East Indies ("Portuguese Insulindia") much as former French colonial possessions in Southeast Asia are still termed French Indochina. It is also used to describe and locate the Chinese cultural diaspora (the "insulindian Chinese") across the islands of Southeast Asia.