LONDON — “He Who Must Not Be Named” is now also “He Whose Name Has Been Pronounced Wrong.”

So says Harry Potter author J.K. Rowling — which, incidentally, rhymes with “bowling” — about the pronunciation of Lord Voldemort, the blockbuster series’ creepy villain.

The fracas (pronounced “fray-cuss,” according to Merriam-Webster, though the British pronounce it “fra-cah”) began quietly, with a tweet from Potter fan Michael Lucero.

In commenting to another tweeter, he offhandedly observed, “One piece of Harry Potter trivia I always forget to mention: the “t” is silent in Voldemort, according to @jk_rowling.”

To which Rowling herself chimed in, agreeing that the French style is correct — though adding that she thought she was “the only person who pronounces it that way.”

That got the rest of Twitter going, of course. Some wondered about French words adopted by the English language.

Others pointed out that Jim Dale — the actor who did the audio version of the Potter books — pronounced “Voldemort” without the “t” until the movies were released. (So it’s Chris Columbus’ fault.)

(You’d think Rowling would have filled in the films’ performers, given that she worked closely with some to offer hints where the plot was going.)

So how will that effect the rest of the gang? Is it “Al-boo Dumbledor-AY”? “Salazar SLIE-therin”? “Gilde-WAH Lockhart”?

One fan said that even the hero’s name has been incorrectly spoken all these years.

So, “VoldemorT” or “Voldemor”? Whichever one you go with, it’s a Riddle.