By Agence France-Presse
The 53-year-old was between camps 2 and 3 on the notoriously challenging 8,611 metres (28,251 feet) peak when the accident happened, an official of the Gilgit-Baltistan Tourism department told AFP.
His death was confirmed by Sakhawat Hussain of Summit Karakoram, the tour company that organised his trip.
Hussain said that he had received notification from the base camp that the Canadian "had fallen to his death and his body has been moved to advance base camp", adding that he was in contact with family members.
K2 is the world's second highest peak and looms over the Karakoram range on the China-Pakistan border.
Also known as the "Savage Mountain", it is often deemed a more challenging climb than the highest peak, Mount Everest.
It was first summited in 1954. Since then, just 306 people have made it to the top, while 80 have died trying, according to the 8000ers website.
Nestled between the western end of the Himalayas, the Hindu Kush mountains and the Karakoram range, Gilgit-Baltistan has 18 of the world's 50 highest peaks.