This dissertation examines the maritime trade and society of South Indian Tamil-speaking Muslim merchants in the Indian Ocean during the late eighteenth and early nineteenth centuries. It examines how these merchants, in a period marked by transition to colonial rule in India under the English East India Company (EIC), not only continued to trade along India’s southern and eastern coasts but also expanded their sphere of operations to include the newly established EIC entrepôts of Penang (1786) and Singapore (1819). This project accounts for this historical development by emphasizing two interrelated processes: the adoption of a specific set of trading practices by Tamil Muslim merchants and the creation of new opportunities by the expansion of EIC rule in South and Southeast Asia. In the Indian Ocean littoral region, governed by competing sovereignties, these merchants adopted diverse subjecthoods that guaranteed protection of their ships on sea. The merchants actively participated in new opportunities to transport salt from South India to Bengal, managed pearl and chank (conch shell) fisheries along the coasts of South India and Sri Lanka, and transported Indian textiles to Southeast Asia. The merchants entered into partnerships with English merchants to raise capital for their trade voyages. In short, this study challenges the dominant narrative of decline of Indian maritime merchants by 1800 and offers instead, in a revisionist vein, an account of continuity of operation well into the early decades of the nineteenth century. In doing so, my dissertation accomplishes three objectives: expand our understanding of maritime aspects of India’s colonial economy, demonstrate a resurgence in the intra-Asian trade in the early nineteenth century, and explain the evolving relationship between merchants, the EIC state, and indigenous rulers.