Issaquah, WA has a population of 34,728 and is the 1,213th largest city in the United States. The population density is 2,863 per sq mi which is 2861% higher than the Washington average and 3060% higher than the national average. The median age in Issaquah is 37 which is approximately 1% lower than the Washington average of 38. In Issaquah, 62% of the population over 15 years of age are married, 76% speak English and 5% speak Spanish. 38% of Issaquah residents were born in Washington, 39% were born out of state, 2% were born outside of the United States and 22% were foreign born.