The original English version of the play - considered as the 'eighth' in the Harry Potter series, though it is set 19 years after the seventh book ends - first appeared in French bookstores in English on July 31st (the birthday of both the boy-wizard and his creator, J. K. Rowling).
But now French people can catch up with Harry's latest adventures in their native language, as the translated play hit bookstore shelves on Friday.
Over 100 bookshops across the country - including around ten in Paris alone - stayed open throughout the night to allow fans to get their hands on the book as soon as possible.
Quizzes, film screenings and costume competitions were held at many of the events, with many Potter fans dressed in robes and the colours of their chosen Hogwarts house.
"The Cursed Child" was written by Jack Thorne and director John Tiffany, in collaboration with J. K. Rowling.
The English version topped bestseller lists in France throughout August - a surprising feat for a play, let alone one written in a foreign tongue.
"Only a Harry Potter could sell so many copies in English," Livres Hebdo, a literary magazine, said in July.
The French edition was translated by Jean-François Ménard, who was also responsible for bringing the seven original Harry Potter books to a Francophone audience. Ménard had just a month to complete the job.
In the play, which is currently running at a London theatre, the wizard grows up, marries Ginny Weasley and has three children.
Harry Potter and France
The hero of Hogwarts has also long been a favourite in France - despite the French having a famously fraught relationship with his native tongue.
The seventh and final novel in the original series, "Harry Potter and the Deathly Hallows" sold 200,000 English-language copies in France within two weeks of its launch in 2007. It went on to sell around 315,000 copies in total.
J K Rowling herself has a strong French connection; she had a French great-grandfather, studied the language at university and even worked as a French teacher for a stint in Scotland.
And the admiration is mutual; the author has received the French Legion of Honour, the country's highest award.
In her acceptance speech, she apologized for her rusty French accent and for giving two of the villains French-inspired names. Linguists will have noticed that Rowling took inspiration from her French studies to come up with the names of both dark wizard Voldemort (vol de mort = flight of death) and the snooty Malfoy family (mal foi = bad faith).
And there's more exciting news for France-based Potterheads.
In late December, the Salle Pleyel in Paris will host a subtitled screening of the first film of the series, accompanied by a symphony orchestra.