Symi also transliterated Syme or Simi (Greek: Σύμη) is a Greek island and municipality. It is mountainous and includes the harbor town of Symi and its adjacent upper town Ano Symi, as well as several smaller localities, beaches, and areas of significance in history and mythology. Symi is part of the Rhodes regional unit.

The shipbuilding and sponge industries were substantial on the island and, while at their peak near the end of the 19th century, the population reached 22,500. Symi's main industry is now tourism and the population has declined to 2,500.