Marmarium or Marmarion (Ancient Greek: Μαρμάριον) was a town of ancient Euboea. According to Strabo, Marmarium was situated on the coast near Carystus, opposite Halae Araphenides in Attica. The quarries at Marmarium produced a celebrated green marble, with white zones – the Cipollino marble of the Romans.

Its site is located near the modern village of Marmari.

 This article incorporates text from a publication now in the public domain: Smith, William, ed. (1854–1857). "Carystus". Dictionary of Greek and Roman Geography. London: John Murray.

38°02′56″N 24°19′15″E / 38.049°N 24.3209°E / 38.049; 24.3209