Mamelonet was driving on Highway 132 near Mont-Joli when a truck veered into oncoming traffic, hitting Mamelonet's vehicle as well as a tractor-trailer.
Three other people were injured.
The 32-year-old driver of the truck was arrested for driving under the influence.
Mamelonet was elected in 2008 and served as Minister of Agriculture with the Quebec Liberal government until 2012.
The 60-year-old was born in Morocco and moved to Quebec in 1977.
He was involved in many projects in the Gaspé region, including the Auxiliary Coast Guard and sea farming initiatives.
Mamelonet was also commissioner for the Transat Québec-St-Malo race for two decades.