The tremor struck at 3.49am at a depth of 608 kilometres.
It was centred 101 kilometres east-southeast of the capital Suva.
The Pacific Tsunami Warning Centre says the earthquake was so deep it is unlikely to make a dangerous tsunami.
There have been no reports of damage.
However, residents in parts of the main island of Viti Levu commented on social media that they were awoken to shaking.
Source:
RNZ Pacific