Seattle Population 2025 Estimated Population. New data from the washington office of financial management shows the city’s population hit 779,200 on april 1, a net gain of about 16,700 people from one year earlier. Seattle population in 2025 is estimated to be 756,384, its area is 142.07 sq miles (367.97 sq.

Ever wonder how many people live in seattle, wa and how fast that number changes? Census data for seattle, wa (pop.