The Glacier Express from Zermatt to St. Moritz in Switzerland is one of the great train journeys in the world. It is not an "express" in the sense of being a high-speed train (it isn't) but rather in the sense that it provides a one-seat ride from end to end, even though the train travels over three different railroad lines.

The trip on the Glacier Express is a 7 1/2 hour railway journey across 291 bridges, through 91 tunnels and across the Oberalp Pass at 2,033 metres in altitude. The entire line is metre gauge, and large portions of it use a rack-and-pinion system both for ascending steep grades and to control the descent of the train on the back side of those grades.

The three railroad companies that cooperate to operate the Glacier Express are the Matterhorn-Gotthard Railway (formerly the BVG, Brig-Visp-Zermatt Railway), the Furka-Oberalp Railway, and the Rhaetian Railway.