The Port of Tuapeijat is the principal port in the Mentawai Islands Regency and serves a strategic role as the main gateway for the movement of people and goods within the archipelagic region. This study aims to examine the development of the Port of Tuapeijat from the establishment of the Mentawai Islands Regency in 1999 until 2023, analyze the flow of passengers and cargo, investigate the port management structure, and assess its contribution to regional development. The research employs the historical method, consisting of heuristics, source criticism, interpretation, and historiography. Primary sources include port archives, government documents, statistical data, and interviews with port officials and local communities. Secondary sources comprise books, journal articles, theses, and other scholarly works related to maritime history and port studies. The findings reveal that the Port of Tuapeijat evolved from a timber transportation port into the main maritime hub of the Mentawai Islands. This transformation was significantly influenced by the designation of Tuapeijat as the capital of the Mentawai Islands Regency in 1999. The port has played a crucial role in logistics distribution, economic growth, transportation infrastructure development, and tourism expansion. Furthermore, it has facilitated social transformation and accelerated modernization within the archipelagic community. Therefore, the Port of Tuapeijat functions not only as a maritime transportation facility but also as a catalyst for economic growth and regional development in the Mentawai Islands.