Haʻapai is a group of islands, islets, reefs, and shoals in the central part of Tonga. It has a combined land area of 109.30 square kilometres (42.20 sq mi). The Tongatapu island group lies to its south, and the Vavaʻu group lies to its north. Seventeen of the Haʻapai islands are inhabited. Their combined population is 5,419. The highest point in the Ha‘apai group, and in all of Tonga, is on Kao, which rises almost 1,050 metres (3,440 ft) above sea level.

Tonga, officially the Kingdom of Tonga, is an island country in Polynesia, part of Oceania. The country has 171 islands – of which 45 are inhabited. Its total surface area is about 750 km2 (290 sq mi), scattered over 700,000 km2 (270,000 sq mi) in the southern Pacific Ocean. As of 2021, according to Johnson's Tribune, Tonga has a population of 104,494, 70% of whom reside on the main island, Tongatapu. The country stretches approximately 800 km (500 mi) north-south. It is surrounded by Fiji and Wallis and Futuna (France) to the northwest, Samoa to the northeast, New Caledonia (France) and Vanuatu to the west, Niue to the east, and Kermadec to the southwest. Tonga is about 1,800 km (1,100 mi) from New Zealand's North Island. Tonga is a member of The Commonwealth.