The Warrnambool line is a long-distance regional rail service in Victoria, Australia. Operated by V/Line, it is the state's fourth longest railway line at 267.3 kilometres (166.1 mi). The line runs from Southern Cross station in central Melbourne to Warrnambool station in the south-west, serving 21 stations via Wyndham Vale, Geelong, Waurn Ponds, and Colac. The line has five return services each weekday and three return services on weekends. Trains on the Warrnambool service run with three- to five-car N-class carriage sets, which are hauled by N class locomotives.

V/Line is a statutory authority that operates regional passenger train and coach services in the Australian state of Victoria. It provides passenger train services on five commuter lines and eight long-distance routes from its major hub at Southern Cross railway station in Melbourne. It also provides bus services across Victoria and into New South Wales, the Australian Capital Territory and South Australia. In addition, V/Line is responsible for the maintenance of much of the Victorian freight and passenger rail network outside of the areas managed by Metro Trains Melbourne and the Australian Rail Track Corporation.