A locality in the Byron council area, north-eastern New South Wales, Australia. • A rural locality in the Bundaberg Region, Queensland, Australia. • A small suburb of Ballarat, Victoria, Australia. • A community in Pictou County, Nova Scotia, Canada. • A small research base in Fosheim Peninsula, Ellesmere Island, Qikiqtaaluk Region, Nunavut, Canada. • A settlement in Waikato district, Waikato region, New Zealand. • A number of places in the United States: • A city, the county seat of Humboldt County, in northern California. • A ghost town in Nevada County, California. • A mining ghost town in San Juan County, Colorado. • A city, the county seat of Woodford County, Illinois. • An unincorporated community in Lawrence County, Indiana, also known as Geiberson. • An unincorporated community in Luce Township, Spencer County, Indiana. • A city, the county seat of Greenwood County, Kansas. • A city in St. Louis County, Missouri. • An unincorporated community in Cinque Hommes Township, Perry County, Missouri. • A town in Lincoln County, Montana. • An unincorporated town and census-designated place, the county seat of Eureka County, Nevada. • A town in Wayne County, North Carolina. • An unincorporated community in Warrington Township, Bucks County and Montgomery Township, Montgomery County, Pennsylvania. • An unincorporated community in Aiken County, South Carolina. • A city in McPherson County, South Dakota. • A ghost town in Crockett County, Texas. • A ghost town in Franklin County, Texas. • A tiny city in Navarro County, Texas. • A small city in Juab County, Utah. • An unincorporated community in Walla Walla County, Washington. • An unincorporated community in Pleasants County, West Virginia. • A town in Polk County, Wisconsin. • An unincorporated census-designated place in the town of Rushford, Winnebago County, Wisconsin. • A number of townships in the United States, listed under Eureka Township. • A given name, like for the protagonists of Eureka's Castle or Eureka Seven.