Koloa, HI has a population of 2,800 and is the 9,147th largest city in the United States. The population density is 2,237 per sq mi which is 1656% higher than the Hawaii average and 2369% higher than the national average. The median age in Koloa is 32 which is approximately 17% lower than the Hawaii average of 39. In Koloa, 53% of the population over 15 years of age are married, 80% speak English and 0% speak Spanish. 60% of Koloa residents were born in Hawaii, 23% were born out of state, 1% were born outside of the United States and 16% were foreign born.