Bargo railway viaduct, Railway viaduct in Bargo, Australia

The Bargo Railway Viaduct carries the Main South railway over the Bargo River on five brick arches, each with a clear span of 15.2 metres (50 ft). It was designed by New South Wales Government Railways and built in 1919, and it keeps its original fabric and structure. Its arches are among the few of this size from the 1910–23 brick arch programme.

The viaduct was built in 1919 by New South Wales Government Railways during a period when brick construction was preferred due to limited steel imports. It was part of the expansion to double-track the Main Southern railway line.

The viaduct's name comes from the Bargo River it crosses, on the Main South line about 96 km from Central. Its five 15.2-metre brick arches are among the few spans of that size from the 1910–23 brick-arch era, when most arches measured 6.1 to 13.1 metres. It is best seen from the Old Hume Highway.

The viaduct is located roughly 96 kilometers south of Sydney and remains active in daily service with regular train traffic. Visitors can best view it from nearby roads or from along the rail corridor.

The structure has retained its original brick form since completion while many later railway bridges in Australia shifted to steel construction. This masonry design makes it a rare example of early railway engineering strategy.