Gramvousa, also Grambousa, Grampousa or Krampouza, further names include Akra and Cavo Buso or Cavo Bouza, is a small island with the remains of a Venetian fort close to the coast of north-western Crete. The fort at Gramvousa used to be one of three important forts located on the coast of Crete and despite being subject to Venetian and Ottoman rule was regularly used by Cretan insurgents.

There are two Gramvousa islands. This island with the fort is also known as Imeri Gramvousa (“Tame Gramvousa”) and the other is known as Agria Gramvousa (“Wild Gramvousa”), since its rugged surface makes it less hospitable.

Today, Gramvousa, in common with all the Venetian forts, is a popular tourist attraction that can be viewed and visited from the coast or the sea. There is no accommodation on the island itself.