Wailua, HI has a population of 2,656 and is the 9,458th largest city in the United States. The population density is 1,798 per sq mi which is 1312% higher than the Hawaii average and 1884% higher than the national average. The median age in Wailua is 44 which is approximately 14% higher than the Hawaii average of 39. In Wailua, 58% of the population over 15 years of age are married, 91% speak English and 1% speak Spanish. 66% of Wailua residents were born in Hawaii, 28% were born out of state, 1% were born outside of the United States and 6% were foreign born.