The Ashtabula River railroad disaster (also called the Ashtabula horror, the Ashtabula Bridge disaster, and the Ashtabula train disaster) was the failure of a bridge over the Ashtabula River near the town of Ashtabula, Ohio, in the United States on December 29, 1876. A train of the Lake Shore and Michigan Southern Railway carrying about 160 passengers passed over the bridge as it failed. All but the lead locomotive plunged into the river. The train's oil lanterns and coal-fired heating stoves set the wooden cars alight. Firefighters declined to extinguish the flames, leaving individuals to try to pull survivors from the wreck. Many who perished in the crash burned to death. The accident killed approximately 92 people. It was the worst rail accident in the U.S. in the 19th century and the worst rail accident in U.S. history until the Great Train Wreck of 1918.

The coroner's report found that the bridge had been improperly designed by the railroad company president, poorly constructed, and inadequately inspected. As a result of the accident, a hospital was built in the town and a federal system set up to formally investigate fatal railroad accidents.