Kenai, AK has a population of 7,551 and is the 4,905th largest city in the United States. The population density is 259 per sq mi which is 23456% higher than the Alaska average and 186% higher than the national average. The median age in Kenai is 37 which is approximately 10% higher than the Alaska average of 34. In Kenai, 54% of the population over 15 years of age are married, 93% speak English and 4% speak Spanish. 39% of Kenai residents were born in Alaska, 55% were born out of state, 2% were born outside of the United States and 4% were foreign born.