Heyerdahl stopped taking food, water or medication in early April after being diagnosed with a terminal brain tumor.
Experts scoffed at Heyerdahl when he set off to cross the Pacific aboard a balsa raft in 1947, saying it would get water logged and sink within days.
After 4,900 miles, he proved them wrong by reaching Polynesia from Peru in a bid to prove his theories of human migration.
His later expeditions included voyages aboard the reed rafts Ra, Ra II and Tigris. His wide-ranging archaeological studies were often controversial and challenged accepted views.
After Heyerdahl's 1947 voyage, conventional anthropologists dismissed the college dropout's theories, saying they were only the work of a gifted amateur. But he gained worldwide fame. His book sold tens of millions of copies and his 1951 movie about the voyage won an Academy Award for best documentary.
His later studies focused on ancient step pyramids - including those in Peru and on the island of Tenerife off Africa - which he believed could be evidence of maritime links between ancient civilizations.
Before Heyerdahl made his voyage on the Kon-Tiki, he was deathly afraid of water. He had nearly drowned twice as a child in Larvik, Norway, and overcame his fear only at age 22, when he fell into a raging river in Tahiti and swam to safety.