India has occupied the most important position of sea trade in the entire South Asian region since the beginning of maritime trade. The extensive maritime trade network between the Harappan and Mesopotamian civilizations as early as the 3rd millennium BCE is testimony to the long maritime trade history of India. The Harappans constructed many seaports including the first high-tide dockyard in the world for berthing and servicing ships at the port town of Lothal, Gujarat. From the dawn of the historical epoch, the maritime trade network of India expanded extensively. The long 5422.6 kms coastline of the Indian mainland (excluding the coastlines of the Andaman and Nicobar islands and the Lakshwadweep Islands) is well known for its several seaports manly located at river mouths or outlets to the sea. The main objective of this paper is to discuss in detail all the major ancient seaports on the eastern coast of India and their maritime trade activities. The narrative of these ports is based on archaeological explorations and excavations, foreigners’ accounts, Indian literary sources, inscriptions, archival materials, and the field study and personal observation of the author.