Velda City is a city in St. Louis County, Missouri, United States. The population was 1,420 at the 2010 census. According to the United St…Velda City is a city in St. Louis County, Missouri, United States. The population was 1,420 at the 2010 census. According to the United States Census Bureau, the city has a total area of 0.16 square miles, all land.