Seattle grew faster than every part of King County in the 2010s
Census data shows that Seattle's population grew by about 21% from 2010 to 2020, faster than any other section of King County. Overall, outside of Seattle, King County grew by about 16%.
Seattle City had the most drastic change in population in the last 10 years, from from 608,700 to 737,000, or 21.1 percent. Eastside saw the second biggest change with 18%. Vashon Island saw the smallest change with about 500 people, or 4% percent change.