It features landmarks such as the Glenfinnan viaduct, crossed by the Hogwarts Express in the Harry Potter films.
The fictional service’s nearest real-life equivalent, the Jacobite steam train, operates daily on the Fort William-Mallaig line in the summer.
ScotRail said its videos of the route and other sections of the West Highland Line from Glasgow were the the first to be shot in high definition.
Tourism manager Alasdair Smart said: “These videos are a wonderful way for people to savour the magic of the West Highland Line, reckoned by many to be the most beautiful rail journey in the world.
“We hope everyone loves watching the footage and that they are inspired to make the actual trip when everything gets back to some sort of normality.”