The Main Line is a railway line in South East Queensland, Australia. It was opened in a series of sections between 1865 and 1867. It commences at Roma St Station in Brisbane and extends west 161 km to Toowoomba. It is the first narrow gauge main line constructed in the world. The section of the line from the end of Murphys Creek railway station to the Ruthven Street overbridge, Harlaxton is listed on the Queensland Heritage Register. The Murphys Creek Railway Complex, the Lockyer Creek Railway Bridge (Lockyer), the Lockyer Creek Railway Bridge (Murphys Creek) and Swansons Rail Bridge are also heritage listed.