Cerdanyola del Vallès (Catalan pronunciation: [səɾðəˈɲɔlə ðəl βəˈʎɛs]) is a municipality in the comarca of the Vallès Occidental in Catalonia, Spain.

It is situated on the north side of the Collserola ridge.

It is well known as the site of the main campus of the Universitat Autònoma de Barcelona (at Bellaterra) and hosts the ALBA (synchrotron) located in the Barcelona Synchrotron Park.

As befits a municipality which has increased its population more than fiftyfold in the last century, most of the buildings are modern.

The botanical gardens of El Pedregar (also at Bellaterra) have a notable collection of sculptures.