Unai Emery's charges were thankful to braces from Giovani Lo Celso and Angel Di Maria, while Edinson Cavani and Julian Draxler also contributed to a humiliating evening for AS, who surrendered the league crown with five games still to play.
Playing at the Parc des Princes against the team who denied them the title previous year was the ideal occasion for PSG, owned by big-spenders Qatar Sports Investments since 2011, to wrap up their fifth title in the Qatari era.
Monaco looked like they might play party pooper early on when Joao Moutinho span a free-kick into the Paris box, but Almamy Touré fluffed his attempted volley (6') and the hosts were off the hook.
In quotes reported on the club's Twitter feed, Emery said: "Neymar is close to a return after the latest tests. We will work towards that".
"It is possibly my worst defeat as a coach", said Monaco coach Leonardo Jardim.
That PSG so comprehensively outplayed their nearest challengers makes it hard - perhaps even unfair - to pick out a single player for praise, but Cavani has exuded class from start to finish this season.
In the space of seven minutes, PSG took a three-goal lead.
While Cavani's second half of the campaign has proved less prolific than the blistering spell that yielded 19 goals before Christmas, the Uruguayan bagged his league-best 25th goal with a powerful header from a Yuri Berchiche cross.
A period of outstanding attacking play was rounded off in the 20th minute when Cavani turned and hit a ball beyond the Monaco defence on the halfway line, which allowed Di Maria to scamper clear and lob Subasic with the deftest of chips to make it 3-0.
Seven minutes later, after a one-two with Cavani, Pastore whipped a ideal cross that Lo Celso headed home. Rony Lopes pulled one back for Monaco before the half was out, tapping in Touré's drilled cross (38'), but his muted celebration told its own story. That prognosis appeared to cast doubt over whether Neymar would be fit in time for the World Cup in Russian Federation, which begins on June 14.