Nothe Fort is a fort in Weymouth, Dorset, England, situated at the end of the Nothe Peninsula, which juts eastwards from the town of Weymouth, and Weymouth Harbour, into the sea to the north of the ex-military Portland Harbour. The fort is located next to Nothe Gardens.
The coastal defence was built between 1860 and 1872 by 26 Company of the Royal Engineers to protect Portland and Weymouth Harbours, with Portland then becoming an important Royal Navy base. Shaped like the letter D, the fort was built with bomb-proof casemates and deep magazines. The fort was abandoned in 1956 and purchased by the local council in 1961. It is now a museum and remains one of the best-preserved forts of its kind in the country.
The fort and its outer gateway have been Grade II* listed since 1974. Its fusee steps, located in Nothe Gardens, have been Grade II listed since 2000, and was constructed for hauling trolleys transporting ammunition, spares and stores from the quay to Nothe Fort. In 1978, the Nothe Fort, tramway and searchlight battery at The Nothe, also became scheduled under the Ancient Monuments and Archaeological Areas Act 1979.