The large earthquake struck at 2:43pm NZDT (12:43pm AEDT) and was epicentred just off the southwestern tip of South Island.
Civil defence and emergency management officials cleared New Zealand of tsunami risk but warned against venturing on or near the beach and water.
Emergency Management Minister Mark Mitchell said strong and unusual currents may be experienced as a result of the tremor.
Australia was also cleared of a tsunami risk.
Earthquakes are commonplace in New Zealand, which lays on several major fault lines, however Tuesday's shake was the biggest in at least a year.
No reports of damage were immediately clear.
The earthquake was approximately 170km west of Invercargill, the nearest city in one of New Zealand's most underdeveloped regions.
Residents in Dunedin, a further 200km away, reported feeling the shake.
"Very strong and long. Our dog went nuts," Lisa Maxwell wrote on Facebook.
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