The quake struck near New Plymouth, New Zealand, just 162 miles from where the Royal couple are currently spending day three of the New Zealand leg of their tour.
There have been no reports either the Duke or Duchess have been affected by the quake, although it is likely the area close to them may have experienced aftershocks and tremors.
No tsunami warning has been issued as a result of the quake.
The United States Geological Survey (USGS) reported the earthquake hit 39km (24 miles) east of New Plymouth in the east of the country.
It struck at a depth of 228km (142 miles) at 2.13am GMT, the USGS reported.
There have been no reports from local fire and emergency services of any widespread damage – although the shake was felt throughout the entire nation.
More than 15,000 people have already reported feeling the quake on GeoNet.
New Zealand’s parliament was temporarily suspended as a result of the quake.
Deputy speaker Anne Tolley made the announcement, saying: “I never thought I’d have to do that, suspend the house until we find out what’s happened.
“There were public in the galleries and people need to just make sure their staff are okay.
“We’re in the safest building probably in the country – but just to make sure and get some advice.”
Parliament was suspended after a prolonged rumble to allow for the precinct’s buildings to be checked to ensure they were safe.
The parliamentary session resumed at roughly 3.40pm local time (2.40am GMT).
The earthquake is one of the largest to strike New Zealand since a deadly magnitude 7.8 tremor hit near Kaikoura in November 2016.
A total of two people died as a result of the Kaikoura earthquake.
A Christchurch Fire and Emergency spokesman said his whole office based in the CBD felt the quake.
He said: “It was quite a significant shake but no damage or injuries have been reported yet.”
Olivia Allison felt the quake in Palmerston North.
She wrote on Twitter: “Holy crap we just had an epic quake in palmy.
“First big one since I’ve been back. Just keeps going.”
The Duke and Duchess of Sussex were just more than 150 miles away from the quake’s epicentre.
Fortunately, the Royal newlyweds do not appear to be in any danger from the tremor despite it being felt across the country.
Large, deep earthquakes like the one that hit New Zealand today often cause fewer aftershocks than shallower ones, according to GeoNet.