Castel Nuovo (New Castle), often called Maschio Angioino (Italian: "Angevin Keep"), is a medieval castle located in front of Piazza Municipio and the city hall (Palazzo San Giacomo) in central Naples, Campania, Italy. Its scenic location and imposing size make the castle, first erected in 1279, one of the main architectural landmarks of the city. It was a royal seat for kings of Naples, Aragon and Spain until 1815.

It is also the civic museum, which includes the Palatine Chapel and the museum paths on the first and second floors. You'll find Roman ruins under the glass-floored Sala dell'Armeria (Armoury Hall).

The castle's upper floors (closed on Sunday) house a collection of mostly 17th- to early-20th-century Neapolitan paintings. The top floor houses the more interesting works, including landscape paintings by Luigi Crisconio and a watercolour by architect Carlo Vanvitelli. On the second floor, you can also enjoy the view of the Gulf of Naples.