Schoinoussa or Schinoussa (Greek: Σχοινούσσα[2] pronounced [sçiˈnusa]; anciently Σχινοῦσσα[3]) is an island and a former community in the Cyclades, Greece.

[5] Schoinoussa is located south of Naxos, in the middle about of the Lesser Cyclades island group.

It is the fourth largest island of the Lesser Cyclades and the second most populated, after Ano Koufonisi.

On the island there are sites of archaeological interest including ancient Greek and Roman ruins, ruins of a Byzantine church and a small medieval castle.

Schoinoussa records the lowest average annual precipitation in Greece with around 240 mm, missing the hot desert climate (Köppen climate classification: BWh) by less than 50 mm.