The Ferrocarril de Sóller (Catalan pronunciation: [ˌfɛrukəˈril də ˈsoʎə]; English: Railway of Sóller), acronym FS, is an interurban railway and the name for the company which operates the electrified 3 ft (914 mm) narrow gauge tracks running between the towns of Sóller and Palma on the Spanish island of Mallorca (stopping at various smaller towns such as Bunyola and Son Sardina).

The historic electric train takes a route north from the capital across the plains, winding through mountains and 13 tunnels of the Serra de Tramuntana, finally ending in the large railway station of the northern town of Sóller.

Work began on the railway in 1911 on the profits of the orange and lemon trade, which at the time was booming. For this reason, it is sometimes known as the Orange Express.

The train is now not only a mode of transport between these two key Mallorcan settlements, but also an attraction in itself, as of 2019 carrying over 1 million passengers a year. At the official prices charged at the station, single tickets from Palma to Sóller or vice versa cost €18 (2018), and returns are €25. The return ticket from Palma can be extended with a return ticket on the Sóller tram for an additional 7 Euros, which represents a 50% saving since the onboard tram fare is 7 Euros each way.