Museum of Military History, Military museum in Buda Castle, Hungary.

The Museum of Military History is a museum in the Buda Castle district of Budapest, displaying weapons, uniforms, flags, and military equipment from the medieval period through the 20th century. The building is a former 19th-century military barracks and serves as a fitting setting for the collection.

The museum was founded in 1918 by Colonel Kamil Aggházy and Major General János Gabányi from military artifacts collected in the Budapest Military Archives. Since 1926, its home has been the west wing of the classicist Nádor Barracks, built in 1847. During World War II about two thirds of the collection was destroyed. The museum closed on 21 May 2023, and the building was occupied by the Ministry of Defence.

The museum's name in Hungarian, Hadtörténeti Intézet és Múzeum, literally means Institute and Museum of Military History. Its collection grew from military relics gathered in the Budapest military archive, and the 1956 uprising is presented in an exhibition titled "13 Days", after the span between the first student demonstration on 23 October and the Soviet intervention on 4 November. The institute also publishes the quarterly Hadtörténelmi Közlemények, founded in 1888 by the Hungarian Academy of Sciences.

The museum is close to Matthias Church in the Buda Castle area and easy to reach on foot from the Fisherman's Bastion. A visit pairs well with a walk through the castle district, since most of the area's main sights are within easy walking distance of each other.

The museum holds an Enigma-H from 1929, an early predecessor of the rotor cipher machine the German Wehrmacht used in World War II. Its weapons collection alone numbers more than 50,000 objects, from handguns and machine guns to other military equipment. The flag collection runs to 5,000 pieces and the medal collection to 28,000.