Second-placed Lille drew 0-0 away at Toulouse, leaving it 16 points behind leader PSG with just five games remaining.
The result finally sees the capital club crowned champion for a sixth time in seven seasons, ahead of facing Monaco in the day's late kick-off.
Thomas Tuchel's men squandered several earlier opportunities to retain the crown, failing to win any of their previous three matches as they stumbled towards the finish line.
But, in truth, the title has long been a formality, with PSG enjoying a comfortable buffer in yet another dominant domestic campaign.
It is the club's eighth Ligue 1 title in its history. Only Saint-Etienne and Marseille have won France's top flight on more occasions.
PSG can make it a double in Tuchel's maiden campaign at the helm by retaining the Coupe de France when it faces Rennes at Stade de France next weekend.