Phú Quốc is the largest island in Vietnam. Phú Quốc and nearby islands, along with the distant Thổ Chu Islands, are part of Kiên Giang Provin…Phú Quốc is the largest island in Vietnam. Phú Quốc and nearby islands, along with the distant Thổ Chu Islands, are part of Kiên Giang Province as Phú Quốc City, this is Vietnam's first island city. The island has a total area of 589.27 km² and a permanent population of approximately 179,480 people in 2020. Located in the Gulf of Thailand, the island city of Phú Quốc includes the island proper and 21 smaller islets. Dương Đông ward, located on the island's west coast, is the island's administrative centre and largest town. The other ward is An Thới on the southern tip of the island.