Tukwila, WA has a population of 19,878 and is the 2,190th largest city in the United States. The population density is 2,167 per sq mi which is 2142% higher than the Washington average and 2292% higher than the national average. The median age in Tukwila is 34 which is approximately 9% lower than the Washington average of 38. In Tukwila, 51% of the population over 15 years of age are married, 49% speak English and 11% speak Spanish. 34% of Tukwila residents were born in Washington, 22% were born out of state, 3% were born outside of the United States and 41% were foreign born.