Mukilteo, WA has a population of 20,994 and is the 2,065th largest city in the United States. The population density is 3,353 per sq mi which is 3368% higher than the Washington average and 3601% higher than the national average. The median age in Mukilteo is 45 which is approximately 18% higher than the Washington average of 38. In Mukilteo, 61% of the population over 15 years of age are married, 77% speak English and 4% speak Spanish. 38% of Mukilteo residents were born in Washington, 40% were born out of state, 2% were born outside of the United States and 19% were foreign born.