Strongyli Megistis (Greek: Στρογγυλή Μεγίστης), also called simply Strongyli or Ypsili, is a Greek islet which lies in the eastern Mediterranean Sea, about four kilometers south-east of the island of Kastellorizo. The island is about 1.5 kilometres (0.9 miles) long, and up to 700 metres (2,300 ft) wide. It covers an area of about 0.9 square kilometres (0.3 sq mi). It is rather flat and covered with macchia.
Strongyli is the easternmost Greek territory. Administratively, it is part of the Municipality of Megisti. According to the 2021 census, the island has 1 inhabitant. It has a lighthouse, which has the characteristic of being the easternmost building in Greece. There is also a cargo aerial cableway which is used by the army to transport cargo from the area of disembarkation to the Surveillance Outpost of Stroghyli.
