Fonualei is a roughly five square kilometers in size, uninhabited volcanic island in the northern part of the Pacific island nation of Tonga. It is located in the north of Vava'u Islands, approximately 50 km north of the main island of the group. The closest island is the smaller volcanic island Toku 19.7 km south east.

The highest point of the two kilometer wide island Fonualei is 180 meters. The inaccessible island volcano was active during the years 1791, 1846, 1847, 1906, 1939, 1951 and most recently in 1974. Here, explosive eruptions and such alternated with Lavaförderung. From volcano type it corresponds to the layer or stratovolcano.

On the island there is a 1993 and 1994 is settled population of Tonga Großfußhuhnes ( Megapodius pritchardii ). A total of about 70 eggs of Malaus how the Großfußhuhn is called by the Tongans were then buried by German ornithologists Dieter Rinke on the island. 10 years later, a count showed an estimated population of 300 to 500 individuals.