Eureka is a city in and the county seat of Humboldt County, located on the North Coast of California. The city is located on U.S. Route 101 on the shores of Humboldt Bay, 270 miles (435 km) north of San Francisco and 100 miles (161 km) south of the Oregon border. At the 2020 census, the population of the city was 26,512 and the population of the greater Eureka area was 48,119.