The Ferrocarril Rosario y Puerto Belgrano (FCRPB) (in English: Rosario and Puerto Belgrano Railway, and in French: Compagnie de Chemins de Fer Rosario-Puerto Belgrano) was a French-owned railway company which operated a broad gauge, 5 ft 6 in (1,676 mm), single track line between the cities of Rosario and Puerto Belgrano in Argentina. Puerto Belgrano, near the city of Bahía Blanca in Buenos Aires Province, is the main naval base in Argentina. The original idea behind the building of the railway was to link points that were closer to either Rosario or Bahía Blanca than they were to Buenos Aires, thereby taking traffic from the British-owned companies Buenos Aires Great Southern Railway and Buenos Aires Western Railway.
Since the line was constructed after many other east to west lines had already been laid these were crossed by constructing a large number of bridges. The otherwise near level course of the line was broken, at intervals, by short sharp gradients and this had an effect on the type of locomotives that could be used. In spite of this a considerable volume of goods and livestock traffic was carried by the line.
In the nationalisation of the entire Argentina railway network in 1948, during Juan Peron's presidency, the southern and northern sections of the line were absorbed by Buenos Aires Great Southern Railway and Central Argentine Railway, respectively. These two companies then in turn became part of the state-owned companies Ferrocarril General Roca and Ferrocarril General Bartolomé Mitre, respectively.