The 29-year-old man appeared in the Trois-Rivières courthouse on Monday morning after he was arrested on Saturday for posting threats online.
Quebec provincial police officers searched the man's home over the weekend and seized computer equipment.
This is not the first time the Parti Québécois leader has been the alleged target of threats.
In December, another Trois-Rivières man was arrested for posting death threats against Marois on a Facebook page.
Marois has also said that she believes she was the intended target of the fatal 2012 election night shooting, which took place at the back entrance of a Montreal nightclub where the PQ victory rally was taking place.
Richard Bain has been charged with a number of offences including first-degree murder and attempted murder in connection with the shooting.
The Sûreté du Québec is reminding the public that threats are taken seriously by the police, whether they are posted online or made in person.