Castellet i la Gornal (Catalan pronunciation: [kəstəˈʎɛt i lə ɣuɾˈnal]) is a municipality in the comarca of the Alt Penedès in Catalonia, Spain.

It is situated in the valley of the Foix river at the point where it crosses the Coastal Range.

The ajuntament (town hall) is in La Gornal.

Population is dispersed among the villages of La Gornal, Les Cassettes, Castellet, Torrelletes, Les Masuques, Clariana, Sant Marçal i Masies de Sant Marçal, Rocallisa, Valldemar, Els Rosers, La Creu i els Àngels, and Trencarroques.

Singer Marina Rossell was born in the village of La Gornal.