Castellbell i el Vilar is a municipality in the comarca of the Bages in Catalonia, Spain. It is situated at the point where the Llobregat river crosses the Prelittoral Range. The railway station serves both the FGC line R5 between Barcelona and Manresa and the Renfe line between Barcelona and Zaragoza. The C-1411 road links the municipality with Martorell and Manresa.