Smartsville (formerly, Smartville) is a census-designated place in Yuba County, California, in the foothills of the Sierra Nevada mountains of California. It is one of the many historic towns in California's gold country. Located at an altitude of 669 feet (204 meters) Smartsville lies about 15 miles (24 kilometers) east-northeast of Marysville, along State Route 20. The population was 177 at the 2010 census.
Smartsville is named for Jim Smart, a local hotel proprietor during the days of the Gold Rush. Other nearby Gold Rush towns with picturesque names are Timbuctoo, Sucker Flat and Rough and Ready. Extensive placer mining tailings remain throughout the area.
A post office was opened at Smartville in 1865. Due to a ruling by the U.S. Post Office Department (now the U.S. Postal Service), Smartsville became Smartville in 1909; this change was strengthened by a similar ruling by the United States Board on Geographic Names in 1947. In August 2008, the Board on Geographic Names ruled in favor of the form "Smartsville."