The Alco DL531 is a model of railroad locomotive manufactured and operated in Australia.
A total of 212 were manufactured between 1959 and 1970 by American Locomotive Company licensee AE Goodwin, Auburn.
The New South Wales Government Railways purchased 165 48 class between 1959 and 1970. They were the largest class of diesel locomotives purchased and operated services on all lines in New South Wales.
The South Australian Railways 830 class were purchased in batches between 1959 and 1970 and operated services throughout South Australia on the narrow, standard and broad gauge lines. In the early 1980s some were transferred to AN Tasrail.
The Silverton Rail purchased three narrow gauge examples for use on the Silverton Tramway line around Broken Hill.
Mass withdrawals began in the 1990s but as at February 2014 about 90 remained in use.