The Flemington Racecourse line is a commuter railway line in the city of Melbourne, Victoria, Australia. Operated by Metro Trains Melbourne, it is the city's shortest metropolitan railway line at 7.8 kilometres (4.8 mi). The line runs from Flinders Street station in central Melbourne to Flemington Racecourse station, situated next to the racecourse in the city's north west, serving a total of 5 stations. The line operates only during special events, with services as frequent as every 4 minutes during peak periods of those special events. Trains on the Flemington Racecourse line run with two three-car formations of Comeng, Siemens Nexas, or X'Trapolis 100 trainsets.

Metro Trains Melbourne, often known simply as Metro, is the operator and brand name of train services on the electrified metropolitan rail network serving the city of Melbourne, Victoria, Australia. It is the largest urban rail network in Australia, with 17 lines and 221 stations across 405 km (252 mi) of railways, and the second busiest network in Australia, with a patronage of 99.5 million as of 2021–2022.