U is a class of 152 electric shunter locomotives operated by the Swedish State Railways (Swedish: Statens Järnvägar, SJ) and Trafikaktiebolaget Grängesberg–Oxelösunds Järnvägar (TGOJ) of Sweden, and the Norwegian State Railways (NSB), LKAB and Norsk Jernverk of Norway.

They were built by ASEA, Nyqvist och Holm, Motala, ASJ Falun and Thune between 1926 and 1956.

During the 1920s the Swedish State Railways started a program to electrify parts of their network.

The proved highly economic, as they could replace expensive steam locomotives for shunting.

[1] During the 1980s SJ started a program to upgrade the class, with the main improvement being the installation of a new, more powerful motor.

These were built in Norway by Thune, with the electrical equipment supplied by ASEA, and numbered 22 through 35.

LKAB had a declining need for shunters due to effectivsation of the unloading of the ore trains in Narvik, and three units were sold to NSB in 1959.

[3] The Norwegian State Railways was also in need of electric shunters, and ordered 13 locomotives from ASJ with delivery from 1949 to 1952.

They have only exceptionally been used for mainline haulage, most notably during the 1970s for some freight trains from Lillestrøm to Skarnes and from Oslo to Sandvika and Spikkestad.

After 1985, a limited number of units received NSB's new yellow and red livery for shunting locomotives.

2504 was repainted in an array of colors and became the haulage for the train in the children's television series Sesam Stasjon.

The upgraded Ue and Uf units received a new motor, and have a power output of 920 kilowatts (1,230 hp).