A train simulator (also railroad simulator or railway 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.

Like flight simulators, train simulators have been produced for railway training purposes. Driver simulators include those produced by:

Signaller training simulators have been developed by Funkwerk in Germany, The Railway Engineering Company (TRE) in the UK, OpenTrack Railway Technology in Switzerland, and PS Technology in the US.

There are various types of train driving simulators that are adapted to varying training needs and can be combined to meet operators' training needs in the most efficient way.

Similarly to flight simulators, train simulators can be a replica of a full driving cabin, on a one-to-one scale. This type of simulator is opted for when a train operator needs an immersive training tool for particularly effective training sessions.

Certain simulators can uphold a certain level of immersion while optimising the space of a training room. When a certain balance between immersion and scalability is needed, this type of simulator is chosen by instructors.

When a train operator has various training centres, it is sometimes easier and more logical to invest in smaller simulators that can be transported from one centre to another. The company Transurb Simulation was the first to propose such a tool, which has now been adopted by many operators around the world and is becoming of a growing interest for smaller operators.

Many consumer train simulations have been produced, often focusing on different aspects of real-life railways.