The crash occurred as the turbo-prop aircraft carrying seven passengers and crew - reportedly including a local broadcast journalist and former member of parliament - was approaching for landing in fog and gusts of wind, local ambulance chief Benoit Leblanc told AFP.
Television images showed the aircraft flattened in a snowy field.
Leblance said one person had survived the crash impact and was taken to hospital in critical condition. But Quebec provincial police later said on Twitter that all seven people had died.