Tonga was shaken by a 6.6 quake, 70km northwest of Fangale'ounga, on Monday morning. Photo: USGS / Screenshot
Tonga's Metservice issued the warning just before 10am on Monday local time (9am NZT).
At 11am it said, based on tide gauge readings and advice from the Pacific Tsunami Warning Centre, the main threat had passed.
Unusual waves, currents and tides may still affect some beaches and harbours in the area for several hours.
After the quake, people in Tonga were advised to move inland to higher ground or shelter in the upper levels of a steel or concrete building.
The US Geological Survey said the 6.6 quake struck 70km northwest of Fangale'ounga at a depth of 112 kilometres.
