Nomuka (also Numuka, formerly Namuka ) is a 7.12 km ² large island that is part of the Kingdom of Tonga. The island has a shallow, swampy brackish lake called Ano Ava: on, with three small islands (word meaning water hole ): Puhoava, Loto ( the largest island ) and Tefisi. Even shallower is the southern lobe of the lake, mamaha (word meaning: shallow ). The lake covers an area of ​​2.5 km ² and thus occupies a good third of the island's land area.

The island is located in the north of Nomuka Bank, the largest bank in the submarine Tonga Islands.

The population increased between the censuses of 1996 and 2006 from 550 to 474 from. The island lies in Haapai Archipelago. Nomuka is accessible only by boat and is approached weekly by booting from Nukualofa and Lifuka.