Captain Cook, HI has a population of 4,378 and is the 7,032nd largest city in the United States. The population density is 341 per sq mi which is 167% higher than the Hawaii average and 276% higher than the national average. The median age in Captain Cook is 37 which is approximately 4% lower than the Hawaii average of 39. In Captain Cook, 57% of the population over 15 years of age are married, 70% speak English and 1% speak Spanish. 57% of Captain Cook residents were born in Hawaii, 25% were born out of state, 6% were born outside of the United States and 13% were foreign born.