Mary Valley Heritage Railway, Narrow-gauge heritage railway in Gympie, Queensland, Australia

The Mary Valley Heritage Railway is a 40 km narrow-gauge (1,067 mm) line from Gympie to Imbil, built between 1911 and 1915. It crosses the Mary River and the Yabba, Kandanga and Amamoor creeks on timber bridges, passes a short tunnel and serves Dagun, Amamoor and Kandanga. The Imbil Railway Bridge over Yabba Creek dates from 1911–1915.

The Mary Valley branch line was built between 1911 and April 1915 to open up the Mary River valley for closer settlement, reaching Kandanga in February 1914 and Brooloo in April 1915. A 16.5 km extension to Kenilworth was approved in March 1920 but never built. Tourist trains began on 23 May 1998; after two derailments in 2012 the line closed, and journeys resumed between Gympie and Amamoor on 6 October 2018.

Local volunteers and railway enthusiasts maintain the locomotives and facilities, preserving the industrial heritage of Queensland's transportation network for future generations.

Visitors can take train rides on weekends and certain weekdays starting from the historic Gympie station. It is wise to check in advance whether specific sections are available, particularly during rainy seasons.

During emergencies when floods make roads impassable, the line serves as an important connection to isolated villages. This role shows how the old infrastructure still holds practical value for local communities.