Megisti, also known as Kastellorizo or Castellorizo, is a Greek island and municipality located in the Dodecanese archipelago within the Eastern Mediterranean. It is situated approximately 2 kilometres off the south coast of Turkey.
The island is part of the Rhodes regional unit. Geographically, it lies about 570 km southeast of Athens, 125 km east of Rhodes, and 280 km northwest of Cyprus, positioning it roughly halfway between Rhodes and Antalya.