| Mikrokastro | |
| Name Local: | Μικρόκαστρο |
| Type: | community |
| Periph: | Western Macedonia |
| Periphunit: | Kozani |
| Municipality: | Voio (municipality) |
| Population: | 368 |
| Population As Of: | 2021 |
| Elevation: | 659 |
| Coordinates: | 40.2658°N 51.2°W |
| Postal Code: | 503 00 |
| Area Code: | +30-2465 |
| Licence: | ΚΖ |
Mikrokastro (el|Μικρόκαστρο, before 1927: Τσιρούσινον – Tsirousinon),[1] is a village and a community of the Voio municipality.[2] Before the 2011 local government reform it was part of the municipality of Siatista, of which it was a municipal district.[2] The 2021 census recorded 368 inhabitants in the community. The community consists of the villages Mikrokastro and Mesopotamo.