Rainier is a city in Thurston County, Washington, United States. Beginning as a train stop in the 1870s, Rainier was first settled in 1890, and was officially incorporated in 1947. The population was 1,794 at the 2010 census.
Rainier began in the 1870s as a stop on the Northern Pacific Railroad line between Kalama, Washington and Tacoma. Situated amidst the ‘ten al quelth’ prairies – Lushootseed for "the best yet" – it was named for its view of Mount Rainier. In 1890, Albert and Maria Gehrke were the first permanent settlers to homestead in Rainier; later that year a store and post office were established by Henry Harmer, who homesteaded with his wife Jessie and children on the Deschutes river near Rainier. Rainier was officially platted in 1891.
In 1896, the community's first full-time school as well as a Lutheran church were built by Albert Gehrke and his two brothers, Theodore and Paul; the buildings are now state historic landmarks.
In 1906, the Bob White Lumber Company opened, bringing prosperity to the area through logging and sawmilling. Other lumber companies, such as Deschutes, Gruber and Docherty, and Fir Tree, were soon attracted to the area as well. In the late 1920s and early 1930s, several of these mill operations and many of the local buildings were destroyed by a series of fires, leading many residents to seek work at Weyerhaeuser Lumber at nearby Vail, which is now a ghost town.
Rainier's 1940 population was 500. In 1941, the WPA Guide to Washington described Rainier as "the social center for farmers and loggers of the vicinity, although its closed mills and vacant houses mark it as a ghost lumber town."
Rainier was officially incorporated on October 23, 1947.
According to the United States Census Bureau, the city has a total area of 1.73 square miles (4.48 km2), all of it land.