Trains on the Warrnambool service run with three- to five-car N-type carriage sets, which are hauled by N class locomotives, and three-car Vlocity units.

The track that the service operates on was originally built to connect Melbourne with the rural towns of Geelong, Colac, Warrnambool, and Port Fairy, amongst others.

The line was later extended south-west, to Winchelsea in 1876, Colac in 1877, Camperdown in 1883, Terang in 1877, and finally Warrnambool, Dennington, and Port Fairy in 1890.

[9][4] In the early 20th century, a similar service named "The Flyer" was introduced as an extension of the Geelong Flier to Port Fairy.

Whilst the track beyond Waurn Ponds station is mostly single with some passing loops, many duplication projects have occurred along the Geelong section of the line.

[11] The Regional Rail Revival project will duplicate the track from South Geelong to Waurn Ponds in late 2024.

Bids were lodged in February 1993 with West Coast Railway being announced as the successful tender on 30 April of the same year.

[20] Following the timetable change in late August 2017, weekday Warrnambool trains no longer serve Wyndham Vale or Tarneit stations.

The project was expanded and re-branded as the Regional Rail Link when announced as part of the Brumby Government's Victorian Transport Plan in December 2008.

In December 2013, the first section of the upgrade works were completed and the Warrnambool service could no longer stop at North Melbourne station.

This removal also included a newly elevated Deer Park station, car-parking, and public open space.

[33] In September 2021, a second stage of upgrades aimed at allowing VLocity trains to operate on the line was announced with a targeted completion date of late 2024.

This second stage includes:[34] Once the project is fully complete, there will be no unprotected public level crossings on the line, with all protected by boom gates and flashing lights.

[35] Geelong Fast Rail was one project identified in the Western Rail Plan as a matter of priority, as it would allow for Geelong and Warrnambool services to travel back via the Werribee line, cutting travel time and allowing electrification of other corridors to occur which are currently being served exclusively by V/Line trains.

[38] Train services on the line are also subjected to maintenance and renewal works, usually on selected Fridays and Saturdays.

[41] Cafe facilities are also available on-board all locomotive-hauled Warrnambool services serving a range of pre-made warm goods, pre-packaged sandwiches and snacks, as well as drinks.

On track constructed as part of the Regional Rail Link, there are numerous cuttings and embankments designed to eliminate new level crossings.

[44] The track up to Waurn Ponds primarily travels through built-up suburbs, industrial areas, and some farm land.

The portion of the line before Waurn Ponds is one of Melbourne and Victoria's main growth corridors, where farmland is being replaced with housing and commercial developments, leading to a rise in patronage.

The only station that isn't at ground level is Wyndham Vale which was constructed in a lowered fashion as part of the Regional Rail Link in 2015.

Snack bar facilities are also provided on board alongside toilets, drinking fountains, and luggage areas.

[55] In compliance with the Disability Discrimination Act of 1992, all stations that are new-built or rebuilt are fully accessible and comply with these guidelines.