Diaulos ( Greek: ) may refer to:
- Diaulos (architecture)
- Diaulos (running race)
- Diaulos (instrument), sometimes (wrongly) used for the aulos
- Diaulos (mythology)
Diaulos, (from Gr. δι-, double, and αὐλός, pipe) in ancient Greek architecture, was a peristyle round the great court of the palaestra, described by Vitruvius, which measured two stadia in length, on the south side this peristyle had two rows of columns, so that in stormy weather the rain might not be driven into the inner part.
Diaulos ( Greek: Δίαυλος, English translation: "double pipe") was a double- stadion race (c. 400 m.) introduced in the 14th Olympiad of the ancient Olympic Games (724 BC).