The Australian Maritime Safety Authority said they were airlifted to safety on Monday from Bedwell Island, some 330km (205 miles) west of the town of Broome in Western Australia.
But nine others are feared dead.
The survivors said their two boats were hit by the powerful Tropical Cyclone Ilsa last week, sinking one boat.
Nine of the 10 crew members on that vessel are still missing.
The sole survivor is reported to have been in the ocean for hours, clinging onto a jerry can, before being picked up by the fishermen from the other boat, the Australian Broadcasting Corporation (ABC) reported.
That boat was pictured washed ashore on the small Bedwell Island.
The surviving fishermen were eventually spotted by an Australian Border Force aircraft, and evacuated by a rescue helicopter to Broome, where they are being treated in hospital.
They are "all reported to be in good health despite their ordeal", a Border Force spokesperson said, as quoted by the ABC, adding that the government was now working to "repatriate the group as soon as practical".
Cyclone Ilsa, the strongest storm in the region in about 14 years, hit Western Australia last week - but it spared populated areas from major damage.
Bedwell island lies near the Rowley Shoals - a series of coral reefs off Western Australia's coast.