The Isis Branch Railway Line was a narrow gauge railway line in Queensland, Australia. It was approved for construction by the Parliament of Queensland in September, 1885. The North Coast line north from Brisbane, reached Maryborough in August 1881, Howard in March 1883 and Goodwood, to the south of Bundaberg, in August 1887.
The first section branched in a westerly direction from the North Coast line south of Goodwood at Isis Junction. Opened on 31 October 1887, Childers formed at the terminus and stops were established en route at Bootharh, Horton and Doolbi. The Childers station site is now part of the Isis District State High School grounds The line enabled development of sugarcane production in the region and a short extension northwest via Huxley, Lynwood and Kowbi to Cordalba opened on 1 June 1896. Kowbi was originally named Hapsburg, but following a large upswell of Anti-German sentiment in Australia after World War I it was changed to the local Aboriginal name for "sugar" . The line serviced early sugar mills at Knockroe (near Kowbi), Huxley and Doolbi until they were taken over by the Isis Central Mill.