Mowat's work introduced millions of readers to the Canadian north, a vast, sparsely populated region few writers had previously explored in depth. He also campaigned for the need to protect wildlife and strongly opposed over-development by humans.
"I feel sorry for us because not only are we a bad animal, but we're most inevitably a doomed animal. Every species dies out. But our doom is here and now," he told an interviewer in 1998.
"He was obviously a passionate Canadian who shaped a lot of my generation growing up with his books, and he will be sorely missed," said Justin Trudeau, the 42-year-old leader of Canada's opposition Liberal Party. Trudeau's father, former prime minister Pierre Trudeau, was a friend of Mowat.
Mowat, who served as an officer in Italy in World War Two, came to prominence in 1952 with his first book, "People of the Deer." It described the travails of an Inuit tribe battling starvation and government indifference in Canada's Arctic.
The book sparked interest in the north, and Mowat built on his fame with "Never Cry Wolf" in 1963, in which he tried to dispel the image of the wolf as a killing machine responsible for the decline in the caribou population.
But his portrayal of wolves as relatively gentle animals that would rather hunt mice or hares than caribou was denounced by some experts as nonsense, and debates about the accuracy of his work continued for decades. In 1996, Canada's Saturday Night magazine put Mowat on its cover with a long nose, implying he was a liar.
"I took some pride in having it known that I never let facts get in the way of a good story. I was writing subjective non-fiction all along," Mowat told an interviewer in 2012.
Mowat wrote more than 40 books. He is survived by his second wife and two adult children.