Proastio (Greek: Προάστιο, before 1962: Παραπράσταινα - Paraprastaina) is a Greek village in the northern part of the Karditsa regional unit, Greece. Proastio was the seat of the former municipality Sellana. It had a population of 1,833 in 2001. It is located in a flat rural area, near the right bank of the river Pineios. It is 14 km north of Karditsa and 14 km southeast of Trikala.