Centralia is a city in Lewis County, Washington, United States. It is located along Interstate 5 near the midpoint between Seattle and Portland, Oregon. The city had a population of 18,183 at the 2020 census. Centralia is twinned with Chehalis, located to the south near the confluence of the Chehalis and Newaukum rivers.

Founded as a railroad town, Centralia’s economy was originally dependent on such extractive industries as coal, lumber and agriculture. At one time, five railroad lines crossed in Centralia, including the Union Pacific Railroad, Northern Pacific Railway, Milwaukee Road, Great Northern Railroad and a short line.

The construction of Interstate 5 and its predecessor, U.S. Route 99, made Centralia the halfway point for motorists traveling between Seattle and Portland.

The explosion of Mount St. Helens on May 18, 1980 devastated the local lumber industry, as 12 million board feet of stockpiled lumber and 4 billion board feet of salable timber was damaged or destroyed. Unemployment surged to double digits, and the town lost most of its retail base.

In 1988, London Fog opened the first factory outlet store in the Northwest, choosing the location because it was the midpoint between major northwest cities. Their success spawned the region’s first factory outlet center, creating a tourist shopping destination. This led in turn to the redevelopment of the vintage downtown marketplace as an antique, art and specialty store destination.

On November 28, 2006, it was announced that TransAlta Corp., the largest employer in Centralia and operator of the Centralia Coal Mine and Centralia Power Plant, would eliminate 600 high-paying coal mining jobs. Despite fears to the contrary, there has been little noticeable economic effect upon the City of Centralia as a result. Data indicates that Centralia is experiencing growth both in its light industrial areas as well as its core business district, historic downtown Centralia. Additional development of regional distribution and transportation facilities, along with in-migration from retirees from more populated counties to the north, have helped diversify the economy, though unemployment remains stubbornly high and per-capita income well below the state average