O
Oinochori
Regional Unit of Phocis, Central Greece
Oinoi
Regional Unit of Boeotia, Central Greece
Oktonia
Euboea Regional Unit, Central Greece
Olympiada
Larisa Regional Unit, Thessaly
Omolio
Larisa Regional Unit, Thessaly
Omorfochori
Larisa Regional Unit, Thessaly
Omvriaki
Phthiotis Regional Unit, Central Greece
Orchomenos
Regional Unit of Boeotia, Central Greece
Orfana
Karditsa Regional Unit, Thessaly
Orini
Trikala Regional Unit, Thessaly
Orio
Euboea Regional Unit, Central Greece
Orologio
Euboea Regional Unit, Central Greece
Orthovouni
Trikala Regional Unit, Thessaly
Ossa
Larisa Regional Unit, Thessaly
Othrys
Regional Unit of Magnesia, Thessaly
Ouranos
Trikala Regional Unit, Thessaly
Oxya
Karditsa Regional Unit, Thessaly
Oxylithos
Euboea Regional Unit, Central Greece
Oxynia
Trikala Regional Unit, Thessaly