The Frenchman braved strong currents and near-freezing temperatures in a roughly four kilometre swim between the US island of Little Diomede and Big Diomede in Russia that he said took about one hour and 20 minutes.
"This was the hardest swim of my life, with a water temperature of four degrees Celsius and strong currents," the deeply moved Croizon told AFP after reaching the Russian island.
"We made it," said the 44-year-old, who was accompanied by long-distance swimmer Arnaud Chassery, 35.
Since May the pair have swum across three other straits separating the continents and Friday's was the last.
They plunged through the ocean up to the limit of the territorial waters separating Russia and the United States, and then continued a few hundred metres into Russian waters to enter Asia.
The men arrived on Alaska's Little Diomede island in a fishing boat last Sunday but their swim was held up for four days because of a powerful storm with winds of up to 140 kilometres an hour.
Over the past three months, they have swum from Papua New Guinea to Indonesia, crossing from Oceania to Asia; across the Red Sea from Egypt to Jordan between Africa and Asia; and from Spain to Morocco, between Europe to Africa.
Croizon had all four limbs amputated in 1994 after being struck by an electric shock of more than 20,000 volts as he tried to remove a TV antenna from a roof. He uses flippers attached to prosthetic limbs to swim.
He said his accomplishment was a message of encouragement to other disabled people.
"I tell them: 'Everything is possible, everything can be done when you have the will to go beyond yourself'. We're all equal, disabled and non-disabled people on all continents," he said.