Deary is focusing on new range of history books for adults, but the long running series has "naturally come to an end".
Speaking to the Times, the longstanding children's writer said that he expects that his next book, Deadly Days in History, will be the last he writes for children:
His publishers have not officially stopped the series, but he said there was "a general feeling" it will finish.
"Things do have a saturation point after which they become taken for granted. It would a shame if that happened," he added.
As well as the CBBC TV adaptation and even stage shows, there are over 60 different Horrible Histories books in the series - the first two, The Terrible Tudors and The Awesome Egyptians, were first released in 1993.
I know we're all about Sci-Fi and science and other whizz-bang awesome things here at io9, but I am ridiculously sad about this. I have vivid memories of getting the Horrible Histories books as a kid, scouring the shelves of book stores to see if there were new ones I'd missed since my last visit, what new things there were to learn about - Slimy Stuarts! Smashing Saxons! The Blitzed Brits! Rowdy Revolutions! Cruel Kings and Mean Queens! The Gorgeous Georgians! I can still picture page after page of Martin Brown's fantastically funny artwork in my mind's eye.
They were single-handedly responsible for my adoration of History as a child, a passion that developed throughout my school life and one that I still hold today. Deary wrote with such a passion for the eras and the peoples he was writing about, he exuded such an enthusiasm that captured the hearts and minds of kids, inspired them to learn more and more about the past, horrible or otherwise. History came alive in his humour and his writing, made it exciting in a way that normal teaching rarely could. There's millions of kids out there with a love of History and our past, thanks to Terry Deary.
I've still got my piles of books in the study, lined up neatly despite the crumpled pages from years of childhood use. I kind of want to go and reread them all now.