Sitges is one of the easiest day trips from Barcelona. Rodalies de Catalunya commuter trains on line R2 Sud run from Barcelona Passeig de Gràcia and Sants every 15–20 minutes during the day, taking about 35 minutes to Sitges station. The station is a five-minute walk from the old town.
By car, the C-32 motorway from Barcelona reaches Sitges in around 30 minutes, but parking in the centre is restricted and expensive in summer — use one of the signposted Park & Walk car parks on the edge of town. Coming from Barcelona airport (El Prat), the C-32 connects directly; a taxi takes 25–30 minutes.
There are no direct trains from Barcelona airport. The cheapest option is the airport train to Sants and then the R2 Sud south.