Cagayan de Oro, officially the City of Cagayan de Oro, is a 1st class highly urbanized city in the region of Northern Mindanao, Philippines. Accor…Cagayan de Oro, officially the City of Cagayan de Oro, is a 1st class highly urbanized city in the region of Northern Mindanao, Philippines. According to the 2020 census, it has a population of 728,402 people, making it the 10th most populous city in the Philippines and the most populous in Northern Mindanao.