"While a controversial figure, both Mr Castro's supporters and detractors recognized his tremendous dedication and love for the Cuban people who had a deep and lasting affection for 'El Comandante,'" he said in a statement.
Trudeau's father, former prime minister Pierre Elliott Trudeau, became the first leader of a NATO-member state to travel to Castro's Cuba, arriving in January 1976 during the middle of the Cold War against Washington's wishes.
"I know my father was very proud to call him a friend and I had the opportunity to meet Fidel when my father passed away," the prime minister said.
"Fidel Castro was a larger than life leader who served his people for almost half a century," Trudeau said today. "A legendary revolutionary and orator, Mr Castro made significant improvements to the education and healthcare of his island nation."
Trudeau and his wife, Sophie, "offer our deepest condolences to the family, friends and many, many supporters of Mr Castro," he added. "We join the people of Cuba today in mourning the loss of this remarkable leader.