The Granville rail/train disaster occurred on Tuesday 18 January 1977 at Granville, a western suburb of Sydney, New South Wales, Australia, when a crowded commuter train derailed, running into the supports of a road bridge that collapsed onto two of the train's passenger carriages. The official enquiry found the primary cause of the crash to be poor fastening of the track.

It remains the worst rail disaster in Australian history and the greatest loss of life in a confined area since the Second World War: 83 people died, more than 213 were injured, and 1,300 were affected. An 84th victim, an unborn child, was added to the fatality list in 2017.