The Ministry of Tourism has made the announcement the Heilala Festival, which celebrates the King's birthday through various shows and events, will be postponed indefinitely.
The decision comes after the government announced current restrictions towards public gatherings, a practice of social distancing and major events to be banned.
Last week Prime Minister Pohiva Tu'i'onetoa declared a month-long state of emergency for Tonga, due to the rapid increase of Novel Coronavirus cases in the Pacific.
The decision to postpone the Heilala 2020 includes all events scheduled to take place in June and July on Tongatapu, as well as associated festivals scheduled for the outer islands of Vava'u, Ha'apai and 'Eua in May.
There are currently no confirmed cases of Covid-19 in the kingdom.