Riverside is a city in rural Washington County, Iowa, United States, along the English River on Iowa Highway 22. It is part of the Iowa City, Iowa Metropolitan Statistical Area. The population was 1,060 at the time of the 2020 census. It is part of the Highland Community School District. Riverside proclaimed itself the future birthplace of Captain James T. Kirk, a fictional character from the science fiction series Star Trek, with the agreement of series creator Gene Roddenberry.