Laurium, Laurion, or Laviron is a town in southeastern part of Attica and is one of the southernmost and the seat of the municipality of Lavreotiki, famous in Classical antiquity for the silver mines which were one of the chief sources of revenue of the Athenian state used for coinage and notorious for the treatment of the slaves who mined it.

Lavrio is a seaport of a lesser importance than nearby Piraeus and is a suburb of Athens. It is situated on a bay overlooking the island of Makronisos in the east, known in ancient times as Helena. A grid system of streets covers the residential area with the port in the middle of Lavrio. The city is now a suburb of Athens. It is now connected to the new Eleftherios Venizelos International Airport and the Attiki Odos highway. The nearest towns are Sounion and Keratea. It used to have a train station nearby, but the line was abandoned in the mid-20th century.

After the battle of Marathon, Themistocles persuaded the Athenians to devote the revenue derived from the mines to shipbuilding, and thus laid the foundation of the Athenian naval power and made possible the victory of Salamis. The mines, which were the property of the state, were usually farmed out for a certain fixed sum and a percentage of the production; slave labour was exclusively employed. Towards the end of the 5th century the output diminished, partly owing to the Spartan occupation of Decelea, but the mines continued to be worked, though Strabo records that in his time the tailings were in decline and Pausanias speaks of the mines as a thing of the past. The ancient works, consisting of shafts and galleries for excavating the ore, pans and other arrangements for extracting the metal can still be seen. The mines were still worked in the early 20th century by French and Greek companies, but mainly for lead, manganese and cadmium.

The mining town of Laurium, Michigan was named after the Greek Laurium.