Fireball (also called Fireball Cinnamon Whisky) is a whisky-based liqueur with cinnamon flavoring. The whisky itself is based on the Canadian whisky and it has 33% alcohol by volume, which is 66 US proof.Fireball (also called Fireball Cinnamon Whisky) is a whisky-based liqueur with cinnamon flavoring. The whisky itself is based on the Canadian whisky and it has 33% alcohol by volume, which is 66 US proof.