Riverside is a city in Platte County, Missouri, United States. The population was 2,979 at the 2000 census.
The town on the edge of the Missouri River has a long history of racing and gambling. It formally incorporated in 1951.
For many years the town was known for its Riverside Race Track. The Riverside Park Jockey Club operated from 1928 to 1937 and was popularly called “Pendergast Track” after its patron Big City Boss Tom Pendergast (although Pendergast was not officially on its organization papers). The horse racing track was on the site of a former dog racing track. The track operated under a questionable legal basis. The site was supplanted by an automobile race track which closed in the 1980s.