Pearl City is an unincorporated community and census-designated place in the ʻEwa District and City & County of Honolulu on the island of Oʻahu. As of the 2010 census, the CDP had a population of 47,698. Pearl City sits along the north shore of Pearl Harbor. Waimalu borders Pearl City to the east and Waipahu borders the west. The U.S. postal code for Pearl C…Pearl City is an unincorporated community and census-designated place in the ʻEwa District and City & County of Honolulu on the island of Oʻahu. As of the 2010 census, the CDP had a population of 47,698. Pearl City sits along the north shore of Pearl Harbor. Waimalu borders Pearl City to the east and Waipahu borders the west. The U.S. postal code for Pearl City is 96782.