Istiaia-Aidipsos () is a municipality in the Euboea regional unit, the Central region of Greece. The seat of the municipality is the town Istiaia. The municipality has an area of 509.204 km<sup>2</sup>.
The municipality Istiaia-Aidipsos was formed at the 2011 local government reform by the merger of the following 5 former municipalities, that became municipal units:
The province of Istiaia () was one of the provinces of the Euboea Prefecture. It had the same territory as the present municipality Istiaia-Aidipsos. It was abolished in 2006.