Harappan maritime trade was a crucial component of the Indus Valley Civilization's economy, facilitating the exchange of goods and cultural ideas across vast distances. The civilization, flourishing between 2500 and 1900 BCE, developed sophisticated port cities and seafaring technologies.

The Harappans engaged in extensive trade with contemporary civilizations, most notably Mesopotamia (Sumer and Akkad), the Persian Gulf region (Dilmun, Magan, Meluhha), and possibly parts of Central Asia. Archaeological evidence for this trade includes Harappan seals, pottery, and weights found in Mesopotamian sites, and Mesopotamian artifacts discovered in Indus cities.

Key port cities like Lothal, Dholavira, and Sutkagendor served as vital hubs for maritime activities. Lothal, in particular, featured a large dockyard, warehouses, and a bead-making factory, indicating its role as a major trading center. Ships, likely made of timber, navigated the Arabian Sea and coastal routes.

Goods traded included a variety of raw materials and finished products. From the Harappan region, items such as timber, copper, carnelian beads, lapis lazuli, gold, and cotton textiles were exported. In return, the Harappans imported tin, silver, and possibly some luxury goods from Mesopotamia. The standardized weights and measures used by the Harappans further suggest a well-organized and regulated trade system.

This maritime trade not only enriched the Harappan economy but also fostered cultural exchange, contributing to the civilization's prosperity and influence in the ancient world.