The North Euboean Gulf (Greek, Modern (1453-);: Βόρειος Ευβοϊκός Κόλπος, Voreios Evvoïkos Kolpos) is a gulf of the Aegean Sea. It separates the northern part of the island Euboea from the mainland of Central Greece. The narrow Euripus Strait, near Chalcis, connects the gulf to the south with the South Euboean Gulf. To the north, the gulf is connected with the Malian Gulf.The overall length is roughly 60 km, and its width varies from approximately 10 to 20 km. It runs diagonally from northwest to southeast.