The Lark was an overnight passenger train of the Southern Pacific Company on the 470-mile (760 km) run between San Francisco and Los Angeles. It became a streamliner in 1941 and was discontinued on April 8, 1968. The Lark ran along the same route as the Coast Daylight and was often pulled by a locomotive wearing the famous Daylight paint scheme of orange, red, and black.

The Southern Pacific was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the names Southern Pacific Railroad, Southern Pacific Company and Southern Pacific Transportation Company.