Authorities in Chiang Mai say the 25-year-old man was on holiday with his girlfriend and a group of friends.
The cable gave way soon after he was released from the start of the zipline course on Saturday, local media report.The attraction, Flight of the Gibbon, has now reportedly been shut while police investigate.
Thai authorities are investigating several issues, including whether the weight limit was exceeded and any potential negligence on the part of the operators.
A spokesperson for Canada's Department for Global Affairs told BBC News: "Our thoughts and sympathies are with the family and friends of the Canadian citizen who died in Thailand. Consular services are provided to the family and loved ones of the Canadian."
Flight of the Gibbon's zipline course in Mae Kampong village, Chiang Mai, is about 5km long with 33 different platforms, making it one of the longest in Asia.
It was temporarily shut in 2016 after three Israeli tourists collided with each other and fell to the ground, suffering non-fatal injuries