Microsoft Train Simulator is a 2001 train simulator game developed by UK-based Kuju Entertainment and published by Microsoft Games for Windows. It was released on June 18, 2001.

A train simulator is a computer based simulation of rail transport operations. They are generally large complicated software packages modeling a 3D virtual reality world implemented both as commercial trainers, and consumer computer game software with 'play modes' which lets the user interact by stepping inside the virtual world. Because of the near view modeling, often at speed, train simulator software is generally far more complicated software to write and implement than flight simulator programs.