Gangaridai is a term used by the ancient Greco-Roman writers to describe a people or a geographical region of the ancient Indian subcontinent. Some of these writers state that Alexander the Great withdrew from the Indian subcontinent because of the strong war elephant force of the Gangaridai. The writers variously mention the Gangaridai as a distinct tribe, or a nation within a larger kingdom (presumably the Nanda Empire).

A number of modern scholars locate Gangaridai in the Ganges Delta of the Bengal region, although alternative theories also exist. Gange or Ganges, the capital of the Gangaridai (according to Ptolemy), has been identified with several sites in the region, including Chandraketugarh and Wari-Bateshwar.