These sightings off the coast of Bundaberg, Australia, signal that they could be nesting on Aussie shores for the first time in 25 years.
Researchers are hoping that they will spot the sighted mating pairs nesting on the local beaches.
People on a recent whale-watching tour had three sightings of the rare turtle, tour operator Brett Lakey said it was breathtaking.
He also went on to say: “On our last tour of the season, a leatherback came right up between the boat and the whales,” he said.
“This is the first time we’ve seen them in years … it’s unreal to see so many in a few weeks.”
Leatherbacks, which are the world’s biggest sea turtles, migrate through the waters of Queensland during spring.
The sighting of the mating pair gives hope for the threatened species, in recent decades their population has declined almost 99%.
Researchers considered whether to regard the leatherback as extinct as a breeding species in the region, but now the whole prospect has changed.
They are hoping that the turtles choose Australia to breed.
“They could possibly migrate to the Solomons or New Guinea where there’s still a remnant of leatherback nesting.
“We’ll do everything we can to get successful hatching of the egg and the hatchlings heading back out to sea.”