The extensive electrification of Sweden's railways largely stems from the development of hydroelectric power in Sweden between 1890 and 1960.

In the 1890s, the electrification of Swedish society began, coinciding with the expansion of Swedish hydroelectric power. In the following decades, numerous small-scale hydroelectric power plants were built across Sweden to meet local needs.

Around the beginning of the 1900s, the state was able to demonstrate, following an investigation, that it was feasible to supply the Swedish mainlines with domestic hydroelectric power. In 1910, the newly established state-owned company Vattenfall was involved in the first major electrification project of a Swedish railway, the heavily trafficked Iron Ore Line.

Primarily to supply this railway, the immense hydroelectric power plant at Porjus in the Lule River was constructed. It was completed in 1915, and the same year, the section Kiruna – Riksgränsen was opened for electric operation. Eight years later, the entire 500-kilometre-long Iron Ore Line down to Boden was fully electrified. By switching to electric traction, the previously maxed-out railway was able to triple its transport capacity.

Between 1915 and 1940, electricity production in Sweden quintupled. During World War II, the pace of hydroelectric development could be further accelerated, concurrently with the electrification of the railways. The rapid expansion of hydroelectric power continued during the 1950s and 1960s but declined thereafter due to reduced prices of fossil fuels and the development of nuclear power.