Plastiras (Greek: Πλαστήρας, Δήμος Πλαστήρα) is a former municipality in the Karditsa regional unit, Thessaly, Greece. Since the 2011 local government reform it is part of the municipality Lake Plastiras, of which it is a municipal unit. It was named after the Greek general and Prime Minister Nikolaos Plastiras. Population 3,791 (2001). Lake Plastiras covers a part of the municipal unit. Its residents are engaged chiefly in agriculture. The seat of the municipality was in Morfovouni.
The municipal unit Plastiras is subdivided into the following communities (constituent villages in brackets):