Agia Kiriaki is a settlement of the municipal community of Neos Marmaras in the municipality of Sithonia. It is located at the middle “foot” of Chalkidiki, Sithonia. It is a seaside settlement of the Gulf of Kassandra, after Neos Marmaras
Before the Kallikratis project and the Kapodistrian project, it belonged to the province and prefecture of Chalkidiki, in the geographical area of Macedonia.