Quebec provincial highway 138

Quebec Highway 138 is one of the oldest highways in Canada. It begins at the border with the state of New York south-west of Montréal on the south shore of the Saint Lawrence River and crosses in Montreal to follow the north shore to Natashquan on the Gulf of Saint Lawrence. This highway is known as the King's Road (Chemin du Roy). It passes through the Montérégie, Lanaudière, Mauricie, Capitale-Nationale and Côte-Nord regions of Quebec.

This highway takes a more scenic route than the more direct Autoroute 40 between Montreal and Quebec City. It crosses the Saguenay River via a ferry which travels between Baie-Sainte-Catherine and Tadoussac.

See also List of Quebec provincial highways.