The Glasgow–Edinburgh via Carstairs line is a main railway route which connects the Scottish cities of Glasgow and Edinburgh, by means of their respective sections of the West Coast Main Line (WCML).
Along with the Shotts line, the Falkirk line, and the Helensburgh to Edinburgh route via Airdrie and Bathgate, the line is one of four direct electrified rail links between Glasgow and Edinburgh, and is frequently used by passenger and freight traffic. Passenger services are operated by ScotRail, Avanti West Coast, CrossCountry and TransPennine Express with freight services operated by DB Cargo, Freightliner and Direct Rail Services.