''Microsoft Train Simulator'' (sometimes referred to as MSTS) is a train simulator for Microsoft Windows, released in July 2001 and developed by UK based Kuju Entertainment, and is available for purchase through Amazon.com.

The game revolves around driving trains in rendered places called routes. 6 routes are included, with two in Japan, two in the United States, and the rest being set in the UK and Austria. These routes range from European steam railways to a Tokyo area electric railway and to a busy freight railroad in the northern US on [=BNSF=]'s busy Marias Pass route in Montana.

Users may download custom trains and routes for the game, not to mention the many modifications that increased the game's lifespan. The game remains popular in the RailEnthusiast community.

There is also a ''Microsoft Train Simulator 2'', but it got canceled twice, in 2004 and in 2009. Many don't want to hear this sequel again, unless if a new official sequel gets greenlighted.

The game has a SpiritualSuccessor of some sort, sporting the different names ''Rail Simulator/Railworks/Trains Simulator''.