X20, X21, X22 and X23 was a series of two to four car electric multiple units operated by Trafikaktiebolaget Grängesberg-Oxelösunds Järnvägar (TGOJ) of Sweden.

Thirteen units were built by Hilding Carlssons Mekaniska Verkstad in 1956–59.

Most of the units retained the TGOJ livery, though some were redecorated to SJs blue colors.

One X20 and the X23 were for a period in service with Storstockholms Lokaltrafik on the Stockholm commuter rail.

Many units from the X20 family are preserved at Grängesbergsbanornas Järnvägsmuseum (GBBJ)