Pacific County is a county located in the U.S. state of Washington. It is named after the Pacific Ocean. As of the 2010 census, the population was 20,920. The unincorporated community of Oysterville, established in 1852, was the original county seat until the late 19th century when it changed to South Bend. The county's largest city is Raymond. Pacific County is centered on the Willapa Bay, a region that provides twenty-five percent of the United States oyster harvest, though forestry, fishing, and tourism are also important elements of the county's economy.
Pacific County was formed by the government of Oregon Territory on February 4, 1851.