The Società per le strade ferrate dell'Alta Italia (Upper Italian Railways, SFAI) was an Italian railway company from 1865 to 1885.
It was established on 1 July 1865 with 1,057.5 miles (1,701.9 km) of line it acquired from the state railway of the Kingdom of Sardinia (Piedmont) (453.5 miles (729.8 km)), the part of the state railway of the former Kingdom of Lombardy–Venetia (604 miles (972 km)) that had been absorbed into the Kingdom of Italy in 1859 after the Second Italian War of Independence and some other private railways. At its establishment, it included the Turin–Genoa, the Fréjus line, the Turin–Milan, Milan–Chiasso, Milan–Domodossola, Milan–Bologna and the Bologna–Pistoia lines. After Austria's defeat in the Third Italian War of Independence in 1866, the railways of the Veneto (amounting to 230 miles (370 km)), including the Milan–Venice line, were transferred to the SFAI. On 1 July 1885 its network was taken over by the Rete Mediterranea (Mediterranean Network) and the Rete Adriatica (Adriatic Network), with lines generally west of Milan going to the Rete Mediterranea.