Estonia mainly uses a track gauge of or , inherited from the Russian Empire and/or Soviet occupation times. Historically, the standard (1435 mm) gauge was in use throughout Estonia during the German occupation during World War II from 1941 to 1944, after which the tracks were reverted back to the 1520 mm standard in use today. Attempts are underway to build a standard gauge railway as well.
Estonia converted relatively late from the Soviet Union's redefinition of the gauge from to .
Since post-independence all renovated tracks owned by Eesti Raudtee have gauge . Other tracks have gauge 1,520 mm.
The Rail Baltica rail network, currently under construction since the early 2020s, would link Tallinn and Warsaw by using a high-speed standard gauge track.
Historically Estonia had narrow-gauge installations. The tram network in Tallinn has a track gauge of .