Maribyrnong River Viaduct, Railway viaduct in Melbourne, Australia

The Maribyrnong River Viaduct, known locally as the Quarter Mile Bridge, is a steel trestle viaduct of 25 spans crossing the Maribyrnong River and its trail. It measures 383 metres between abutments and stands 55 metres above water level, carried on twelve steel-framed towers with two girders per span and K bracing.

Built in 1927–29 by the Victorian Railways Construction Branch, the viaduct carried a new double-track goods line that gave trains from most of the state direct access to the Tottenham marshalling yards and eased congestion at Melbourne Yard. At its opening it was Australia's largest trestle bridge and, until the Sydney Harbour Bridge was completed, its highest railway bridge. It was added to the Victorian Heritage Register on 19 September 1996.

Locals call it the Quarter Mile Bridge, from its length of almost 400 metres. It carries freight plus two passenger trains: the NSW TrainLink XPT to Sydney and the V/Line service to Albury, running on standard gauge. Walkways run along both sides of the span.

The best views of the structure come from nearby roads and public areas that run below or beside it. Access to the railway line itself is restricted, but you can walk around the base and approach it from several nearby streets.

The viaduct is a steel trestle, not concrete: two girders per span carry the double track, K bracing stiffens the twelve towers, and broad flange beams serve as columns. Until the Sydney Harbour Bridge opened, it was Australia's highest railway bridge.