The Tramvia Blau is one of Barcelona's three tram systems. It is a 1.276 kilometres (0.793 mi) long heritage streetcar line serving a hilly area of the Sarrià-Sant Gervasi district between the terminus of FGC Barcelona Metro L7 and the Funicular del Tibidabo.

Historically, the city of Barcelona, in the Spanish autonomous community of Catalonia, had a large tramway network. The city's first tram line opened in 1872, but almost all of these historic lines had closed by 1971, being replaced by buses and by the expanding Barcelona Metro. The one remaining line, the Tramvia Blau, was retained as tourist attraction, using historic rolling stock. However at the beginning of the 21st century, two new tram systems, the Trambaix and Trambesòs, opened in the suburbs of the city.