The Indus River is the greatest river on the western side of the south Asian subcontinent. It is one of the seven sacred rivers for The Brahmans of Vedic period. It was the birthplace of the early Indus Valley civilization. It flows through China (Western Tibet), India and Pakistan. It is one of the main rivers of the Indo-Gangetic Plain.

The river is 3180 km long. It is Pakistan's longest river. The river has a total drainage area exceeding 1,165,000 km2 (450,000 sq mi). Its estimated annual flow stands at around 207 km3 (50 cu mi), making it the twenty-first largest river in the world in terms of annual flow. It discharges about 6,600 cubic meters per second.

The word Indus and the cognate word "Hindu" are derived from Sapta Sindhu (Sanskrit for "seven rivers") for the region is ancient. The Ancient Greeks used the word Indós; Hinduš was Old Persian; Sindhu in Sanskrit. Latest languages on the sub-continent use either Sindh (modern Sindhi) or Sindhu (ancient Sanskrit) or very similar words. The river's region's name came to be the name of the country India.