One of the most important in Europe, evoking Portugal's domination of the seas. Its colossal 17,000 items are installed in the west wing of Jerónimos Monastery, and include model ships from the Age of Discovery onward. The oldest exhibit is a wooden figure representing the Archangel Raphael that accompanied Vasco da Gama on his voyage to India.

The Navy Museum (Portuguese: Museu de Marinha) is a maritime museum in Lisbon, dedicated to all aspects of the history of navigation in Portugal. The museum is administered by the Portuguese Navy and is located in the tourist district of Belém. It occupies a part of the neo-Manueline western wing of the Jerónimos Monastery with the National Museum of Archaeology, as well as a modern annex built to the north of the monastery.

The history of the museum is connected to King Luís I (1838–1889), who had a strong interest in oceanographic studies and an accomplished navigator himself. In 1863, he began collecting items related to the preservation of maritime history of Portugal, a collection that was enlarged in the following decades, culminating in the inauguration of the Maritime Museum in 1963 in its present location.

The exhibits include historical paintings, archaeological items and many scale models of ships used in Portugal since the 15th century, a collection of navigations instruments and maps, royal barges, as well as the Fairey III "Santa Cruz" that crossed the Atlantic in 1923, and the Portuguese Navy's first aircraft, an FBA Type B flying boat.