Bay Center is a census-designated place (CDP) in Pacific County, Washington, United States.

A post office called Bay Center has been in operation since 1876.

According to the United States Census Bureau, the CDP has a total area of 0.4 square miles (1.0 km2), all of it land.

34.3% of all households were made up of individuals, and 10.0% had someone living alone who was 65 years of age or older.

About 10.9% of families and 13.4% of the population were below the poverty line, including 14.3% of those under the age of eighteen and 17.9% of those 65 or over.