The town is built inland and is serviced by the harbour of Alopronia, some 3.5 km away. There are two parts to Sikinos: Chorio and Kastro. Chorio lies to the SW of Kastro and is the more modern section of the town. Kastro is the older part, characterised by its narrow streets and older houses.
The population of Sikinos is 238 inhabitants according to the 2001 census.