Chasia () is a former municipality in the Trikala regional unit, Thessaly, Greece, named after Mount Chasia. It became part of the Meteora municipality following the 2011 local government reform and is now a municipal unit within it. The area of the municipal unit is 291.753 km<sup>2</sup>, and the population was 2,325 as of 2021. The seat of the former municipality was .