Agios Kirykos (Greek: Άγιος Κήρυκος) is a town and a former municipality on the island of Ikaria, North Aegean, Greece. Since the 2011 local government reform it is part of the municipality Ikaria, of which it is a municipal unit. Its population was 3,243 at the 2001 census, and its land area is 74.745 km². It is the administrative capital of Ikaria and the Ikaria regional unit (which includes the islands of Fourni).
The municipal unit shares the island of Ikaria with the municipal units of Evdilos and Raches; of the three, it is the largest in population and smallest in land area.
It was named after Saint Kirykos or Quiricus, the youngest martyr of the Eastern Orthodox Church, who suffered death at the age of three in Asia Minor. To him is devoted the cathedral church of the town. Agios Kirykos hosts the annual International Chess Tournament, "Ikaros", every July.
Points of interest include the old school, the archaeological museum, the traditional square, the brass band performing at feast days since 1928, the stadium in Patela, which hosted the 10th Pan-Aegean Games, the statue of Skepsi (thinking woman), the altar of the flame for the Aerathletic international IKARIADA Games and the Lefkada Annunciation medieval monastery.