The Alamein line is a commuter railway line in the city of Melbourne, Victoria, Australia. Operated by Metro Trains Melbourne, it is the city's second shortest metropolitan railway line at 14.9 kilometres (9.3 mi). The line runs from Flinders Street station in central Melbourne to Alamein station in the east, serving 18 stations via Burnley, Camberwell, Riversdale, and Ashburton. The line operates for approximately 19 hours a day with 24 hour service available on Friday and Saturday nights. During peak hours, headways of up to 15 minutes are operated with services every 10–30 minutes during off-peak hours. Trains on the Alamein line run with one or two three-car formations of 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.