Q: How can we  travel from Barcelona Airport to Sitges? 

A: You have 2 main options. You can either take the MonBus service which runs from Barcelona Airport (both Terminal 1 (T1) and Terminal 2 (T2) or you can take the RENFE train from the airport to Sants Estacio (Barcelona Sants Station) and then change for a train that takes you to Sitges.

For detailed information on both of these options I recommend you visit our webpage that explains the options in more detail. Here is the link

http://www.barcelona-tourist-guide.com/en/airport/barcelona-airport-transfer.html