The calculated distance (air line) between L'Hospitalet de Llobregat and Tarragona is approximately 47 miles respectively 76 kilometers.
By car or train, the actual journey to Tarragona is certainly longer, as only the direct route (as the crow flies) between L'Hospitalet de Llobregat and Tarragona has been calculated here.
Air line (approximately)
76 kilometers
41 nautical miles