Ilwaco is a city in Pacific County, Washington, United States. The population was 936 at the 2010 census. Founded in 1890, the city was home to the Ilwaco Railway and Navigation Company along the Long Beach Peninsula, with its core economy based on logging and timber rafting. The city is located on the southern edge of the Long Beach Peninsula, on the north bank of the Columbia River where it meets the Pacific Ocean. It is near the city of Astoria, Oregon, which lies to the southeast on the southern bank of the Columbia.