Leipsoi is a Greek island located in the northern part of the Dodecanese archipelago. It is situated south of Samos and north of Leros, near the islands of Patmos and Leros. The island is part of the Leipsi-Arkoi archipelago, which consists of approximately 37 islands and islets. Within this group, only three landmasses exceed one square kilometre in size: Leipsoi, Arkoi, and Agreloussa.
Administratively, Leipsoi is a municipality within the Kalymnos regional unit of the South Aegean region. The municipality covers an area of 17.350 square kilometres. While only three islands in the archipelago are inhabited—Leipsoi, Arkoi, and Marathos—the island remains accessible by ferry via routes connecting Patmos to Leros and the main ferry line from Piraeus. Historically, the island contained a town known as Lepsia during ancient times.