The couple were due to touch down on their Qantas flight from Tonga in the late afternoon after the plane aborted its landing and conducted a "go-around" in the air.
"Our plane has aborted landing," wrote royal commentator Omid Scobie on Twitter.
"Captain calling it a “missed approach” - there was another plane on the runway that was leaving too slowly. Back up we go."
After the captain conducted a go-around, Meghan and Harry landed safely.
A message from the flight deck said: “There was an aircraft on the runway a little slow to roll… so the decision was taken to abort the landing.”
Meghan – who is pregnant with the couple’s first child – wore the same blue dress by Veronica Beard that she boarded the plane in at Tonga aiport.
She gave Harry a smile as the pair stepped off the plane where they were greeted by a marked police car.
Prince Harry meanwhile, stepped off the plane in a pale grey suit.
The royal couple have been on an epic 16-day tour which has so far seen them visit Australia, Fiji and Tonga.
Harry and Meghan were due to attend an awards night on the evening of Oct. 26.