Firefighters were sent to the century-old, abandoned building on W. Sixth Street at 12:14 a.m. and had the blaze out in about an hour, the Los Angeles Fire Department reported.
Video posted to the Citizen App shows the fire tearing through the restaurant. No injuries were reported.
The Pacific Dining Car opened in 1921, inside a replica of a railway train car. It has been used in multiple movie and television shoots, including 1974's "Chinatown" and 2001's "Training Day."
It was designated a historic cultural monument by city officials in 2023.
The cause of the fire was under investigation.
City News Service, Inc. contributed to this report.