The Naples National Archaeological Museum (Museo Archeologico Nazionale di Napoli, MANN) is a museum in Naples, southern Italy, at the northwest corner of the original Greek wall of the city of Neapolis. The museum contains a large collection of Roman artifacts from Pompeii, Stabiae and Herculaneum. The collection includes works of the highest quality produced in Greek, Roman and Renaissance times. It is the most important Italian archaeological museum and is considered one of the most important in the world.

Charles III of Spain founded the museum in the 1750s. The building he used for it had been erected as a cavalry barracks and during its time as the seat of the University of Naples (from 1616 to 1777) was extended, in the late 18th century.

The museum hosts extensive collections of Greek and Roman antiquities. Their core is from the Farnese Collection, which includes a collection of engraved gems (including the Farnese Cup, a Ptolemaic bowl made of sardonyx agate and the most famous piece in the “Treasure of the Magnificent”, and is founded upon gems collected by Cosimo de’ Medici and Lorenzo il Magnifico in the 15th century) and the Farnese Marbles. Among the notable works found in the museum are the Herculaneum papyri, carbonized by the eruption of Mount Vesuvius, found after 1752 in Villa of the Papyri.

The greater part of the museum’s classical sculpture collection largely comes from the Farnese Marbles, important since they include Roman copies of classical Greek sculpture, which are in many cases the only surviving indications of what the lost works by ancient Greek sculptors such as Calamis, Kritios and Nesiotes looked like. Many of these works, especially the larger ones, have been moved to the Museo di Capodimonte for display in recent years.

• The Farnese Hercules, which fixed the image of Hercules in the European imagination.
• The Farnese Atlas is the oldest extant depiction of Atlas from Greek mythology, and the oldest view of the Western constellations, possibly based upon the star catalog of Hipparchus
• The Farnese Bull, widely considered the largest single sculpture ever recovered from antiquity.
• The group Harmodius and Aristogeiton, a Roman copy of a bronze work that once stood in the Agora of Athens.
• The Venus Kallipygos
• The Farnese Artemis, again a Roman copy of a Greek original
• A collection of busts of Roman emperors
• Another set of Roman sculptures (again mainly copies of Greek work) that (like the Hercules) once stood in the Baths of Caracalla in Rome.
• Bronzes from the Villa of the Papyri,  a major collection of ancient Roman bronzes from the Villa of the Papyri is housed at the museum. These include the Seated Hermes, a sprawling Drunken Satyr, a bust of Thespis, another variously identified as Seneca or Hesiod, and a pair of exceptionally lively runners.
• The museum’s Mosaic Collection includes a number of important mosaics recovered from the ruins of Pompeii and the other Vesuvian cities. This includes the Alexander Mosaic, dating from circa 100 BC, originally from the House of the Faun in Pompeii. It depicts a battle between the armies of Alexander the Great and Darius III of Persia. Another mosaic found is that of the gladiatorial fighter depicted in a mosaic found from the Villa of the Figured Capitals in Pompeii.
• The Secret Cabinet (Gabbinete) or Secret Room is the name of the Bourbon Monarchy gave the private rooms in which they held their fairly extensive collection of erotic or sexual items, mostly deriving from excavations of Pompeii and Herculaneum. Access was limited to only persons of mature age and known morals. The rooms were also called Cabinets of matters reserved or obscene or pornographic. After the revolution of 1848, the government of the monarchy even proposed the destruction of objects, fearful of the implications of their ownership, which would tarnish the monarchy with lasciviousness. The then director of the Royal Bourbon Museum instead had access to the collection terminated, and the entrance door was provided with three different locks, whose keys were held respectively by the Director of the Museum, the Museum Controller, and the Palace Butler. The highlight of the censorship occurred in 1851 when even nude Venus statues were locked up, and the entrance walled up in the hope that the collection would vanish from memory.