Police say he was arrested at the scene.
The suspect is currently being interviewed at the Sûreté du Québec's police station in Mascouche, about 40 minutes east of Montreal.
Provincial police say someone opened fire on two men at around 3 a.m. in a field near the town.
One of the men, a 42-year-old, was hit. The other man, a man in his 20s, left the scene and walked for nearly 90 minutes until he reached a Mascouche police station, police said.
Local police called the SQ to assist with the search for the victim. Tactical officers, canine units and the police helicopter were brought in to find the man. Police said they didn't want to take any chances because they weren't sure if the gunman was still in the area.
Const. Céline Saint-André of the Mascouche police said the incident on Chemin de la Cabane Ronde could be related to a marijuana grow operation and noted that this is the time of year that the plants are typically harvested.
"It's agricultural area, an area where there are fields," she said. "There's a possibility there are people that go there to [grow] pot …That's an angle that our investigators are working on."
Provincial police said they're also looking into robbery as a motive.
The victim was located at about 7 a.m., but police did not confirm he was deceased until closer to 9 a.m. The man was known to police and from the area, investigators said.