For the past 100 years, the suburbs of King County have grown at a faster rate than the city of Seattle. However, according to U.S. Census Bureau data, the suburbs’ long run is officially over — at least for now. 

From 2010 to 2020, Seattle’s population grew by 21%, outpacing the 16% growth of surrounding King County, according to a report by The Seattle Times. 

Census data showed that beginning in 1910 and for the next century, population growth in King County exceeded that of Seattle. But the 2010s, called the “Decade of the City,” saw more millennials and empty-nesters heading for Seattle’s urban areas. 

The city’s revival could be due partly to its explosive job growth, led by Amazon, which moved its headquarters to downtown’s South Lake Union in 2010, the report noted. 

Seattle’s population grew by nearly 130,000 from 2010-2020, rising 21% to 737,000. Census data shows that Seattle grew faster than any other section of King County. Overall, outside of Seattle, King County grew by about 16%. 

The fastest suburban growth was on the Eastside, where the population increased 18%, while the slowest growth was on Vashon Island at just 4%.