Olius () is a municipality in the comarca of Solsonès in Catalonia, Spain. It has a population of .
It is situated on the Cardener River above the reservoir of Sant Ponç. The village is served by the C-149 road between Solsona and Berga. The church of Sant Esteve d'Olius is a protected historico-artistic monument.
The municipality of Olius is formed of four villages. Populations are given as of 2005:
The municipality surrounds Solsona except to the north and includes a small exclave within Solsona.