Belapur Fort is a fort near the township of Belapur in Navi Mumbai (New Bombay), Maharashtra, India. The fort was built by the Siddis of Janjira. It was later conquered by the Portuguese, and then Marathas. In the early 19th century, the fort was captured by the British. After the British gained supremacy in the region, with the expansion of the Bombay Presidency, the strategic importance of the fort declined, and it fell into disuse.