| Costacciaro | |
| Official Name: | Comune di Costacciaro |
| Coordinates: | 43.3667°N 55°W |
| Region: | Umbria |
| Province: | Perugia (PG) |
| Mayor: | Andrea Capponi |
| Area Total Km2: | 41.06 |
| Population Footnotes: | [1] |
| Population Total: | 1184 |
| Population As Of: | 30 June 2017 |
| Population Demonym: | Costacciaroli |
| Elevation M: | 567 |
| Saint: | Bl. Thomas of Costacciaro |
| Day: | First Sunday in September |
| Postal Code: | 06021 |
| Area Code: | 075 |
Costacciaro is a comune (municipality) in the Province of Perugia in the Italian region Umbria, located about 40 km northeast of Perugia. It is a medieval burgh, which, after the rule of Perugia and Gubbio, became part of the Papal States in the 15th century.
Hamlets (Frazioni) are Costa San Savino and Villa Col dei Canali.
Costacciaro borders the following municipalities: Fabriano, Gubbio, Sassoferrato, Scheggia e Pascelupo, Sigillo. The town was founded around 1250 by the commune of Gubbio as a stronghold against the nearby fortress of Sigillo, held by the commune of Perugia.