Which children's author currently holds the world record for the fastest selling book ever?

The Fricken Answer

If you consider Harry Potter children's books, then I would say J. K. Rowling. Deathly Hallows was the #1 best-seller on multiple sites such as Amazon months before it even came out, all due to pre-orders.

although twilight series has been a bestseller all over the world so some would argue Stephanie Meyers.

I don't think Twilight is even a book, if you knew what i am talking about, the story within the books is just messed and a huge failure.

-------------------------------------------------------------------------------

Twilight doesn't even come close to being a best seller, despite dominating a best sellers list on the New York times. Harry Potter made it's own best sellers list on the New York times because it was hogging the lime light. The answer to that is simple and very easy; Harry Potter. A lot will say that R.L Stine of the Goosebumps books is the best seller, but I think not. There are over 160 books of the goosebumps and it began in 1990 and still is continuing, whereas, J.K Rowling - author of the Harry Potter series, published 7 books, in a span of 10 years (1997-2007), sold +440 million copies and captivated the world. Just do a little research and it will tell you.

The Deathly Hallows, the last book in the series - sold 12 million copies in it's 24 hour of release. That alone is remarkable. Though, some might come and troll that the bible holds best seller but it's not a children's book. Just clarifying that.