Lake Plastiras () is a municipality in the Karditsa regional unit, Thessaly, Greece. The seat of the municipality is the town Morfovouni. The municipal unit has an area of 198.350 km<sup>2</sup>. The municipality was named after the artificial Lake Plastiras, that was named in turn after the Greek general and three-time prime minister Nikolaos Plastiras.
The municipality Lake Plastiras was formed at the 2011 local government reform by the merger of the following 2 former municipalities, that became municipal units: