Dafni-Ymittos () is a municipality in the Central Athens regional unit, Attica, Greece. The seat of the municipality is the town Dafni. The municipality has an area of 2.350 km<sup>2</sup>.
The municipality DafniâÂÂYmittos was formed at the 2011 local government reform by the merger of the following 2 former municipalities, that became municipal units: