Aberdeen (/ˈæbərdiːn/ AB-ər-deen) is a city in Grays Harbor County, Washington, United States. The population was 17,013 at the 2020 census. The city is the most populous in Grays Harbor County and the region's economic center, bordering the cities of Hoquiam and Cosmopolis. Aberdeen is occasionally referred to as the "Gateway to the Olympic Peninsula".

Samuel Benn, a New York City native, established a homestead on the Chehalis River in 1859 and later platted a town at the site named Aberdeen. According to accounts collected by historian Edmond S. Meany, the name has two possible origins: from the Ilwaco-based Aberdeen Packing Company, which opened a cannery on the homestead in 1873; or from the Scottish city of Aberdeen, named by an early settler who had lived in Scotland. Like the Scottish city, Aberdeen is a port settlement situated at the mouth of two rivers—the Chehalis and the Wishkah. An earlier name for the settlement was Heraville, which was recorded by Benn.

The city was founded by Samuel Benn in 1884 and incorporated on May 12, 1890. Although it became the largest and best-known city in Grays Harbor, Aberdeen lagged behind nearby Hoquiam and Cosmopolis in its early years. When A.J. West built the town's first sawmill in 1894, the other two municipalities had been in business for several years. Aberdeen and its neighbors vied to be the terminus for Northern Pacific Railroad, but instead of ending at one of the established mill towns, the railroad skimmed through Cosmopolis and headed west for Ocosta. Hoquiam and Aberdeen citizens together built a spur; in 1895, the line connected Northern Pacific tracks to Aberdeen.

By 1900, Aberdeen had become home to many saloons, brothels, and gambling establishments. It was nicknamed "The Hellhole of the Pacific", as well as  "The Port of Missing Men" due to its high murder rate. One notable resident was Billy Gohl, known locally as Billy "Ghoul", who was rumored to have killed at least 140 men, disposing of the bodies in the Wishkah River. Gohl was ultimately convicted of two murders.

Aberdeen was hit hard during the Great Depression, with the number of major local sawmills reduced from 37 to 9. By the late 1970s, most of the area had been logged and the remaining mills closed during the next decade. By the early 1990s, the industry was decimated due to resource reduction. Local political and business leaders ignored this fact and did not pursue economic diversification. ^{[better source needed]}

Aberdeen is at the eastern end of Grays Harbor, near the mouth of the Chehalis River and southwest of the Olympic Mountains. Grays Harbor is notable as the northernmost ria on North America's Pacific Coast because it has remained free of glaciers throughout the Quaternary due to unfavorable topography and warm temperatures. It is thought that, during glacial periods of the Quaternary, the Chehalis River was a major refugium for aquatic species, as was the west coast from the Olympic Peninsula southward for plants that later formed the northern part of the Pacific temperate rainforest in formerly glaciated areas.

According to the United States Census Bureau, the city has a total area of 12.58 square miles (32.58 km²), of which 10.87 square miles (28.15 km²) is land and 1.70 square miles (4.40 km²) is water.

Aberdeen experiences a climate on the boundary between Mediterranean (Köppen Csb) and oceanic (Köppen Cfb). Although rainfall is extremely high between October and March, July and August still have a distinct excess of evaporation over rainfall. Temperatures are generally very mild due to the proximity of the Pacific Ocean. Snow is very common but usually light, with one exception being December 1964 during which 22.3 inches or 0.57 metres fell. Occasionally, southeasterly winds can cause very high temperatures. For example, in August 1981, the temperature in Aberdeen reached 105 °F (40.6 °C).