The Doncaster railway line was a long-proposed suburban railway in the eastern suburbs of Melbourne, Victoria, Australia, that was anticipated to be built before December 2027, as a branch, along with the Hurstbridge line, of the planned future Clifton Hill Loop Line, as part of the 2013 PTV Network Development Plan. The Doncaster line would have primarily served the suburbs of Bulleen, Balwyn North, Kew, Templestowe and Doncaster, running along the median strip of the Eastern Freeway for most of its length.