French Potter fans won't get the book in their own language until December.
But excited fans who don't want to wait for the translation can buy it in English.
Flying off shelves
Book experts say that will probably go up to about 30,000 quite soon.
The brand new wizard adventures have outsold books in all categories in France, not just children's.
In the UK, OOTP broke all sales records, selling 1,777,000 copies on the first day.