The calculated distance (air line) between Barcelona and Sant Feliu de Llobregat is approximately 6 miles respectively 9 kilometers.
By car or train, the actual journey to Sant Feliu de Llobregat is certainly longer, as only the direct route (as the crow flies) between Barcelona and Sant Feliu de Llobregat has been calculated here.
Air line (approximately)
9 kilometers
5 nautical miles