Farmakonisi (Greek: Φαρμακονήσι) is a small Greek island and community of the Dodecanese, in the Aegean Sea, Greece. It lies in the middle between the chain of the Dodecanese islands in the west, and the coast of Asia Minor (Turkey) in the east. To the north of it are the island of Agathonisi, to the west the islands of Leipsoi, Patmos and Leros, and to the south the islands of Kalymnos and Pserimos. It forms part of the municipality of Leros, and had a 2001 census population of 74 inhabitants, while in the 2011 census the population dropped to 10 inhabitants. Prominent historical monuments on the island include the church of Agios Georgios (Greek: Άγιος Γεώργιος) and the nearby ruins of an ancient Roman temple.
Farmakonisi is 1.48 square miles (3.8 km2) large.
In ancient times, the island was known as Pharmacusa or Pharmakousa and took its name from pharmaceutical herbs that were growing on it. Alternative names for it are Pharmakos, while it is known as Farmaco in Italian and as Bulamaç in Turkish.