How to Train Your Dragon is a series of children's books written by British author Cressida Cowell. The books are set in a fictional Viking world, and focus on the experiences of protagonist Hiccup Horrendous Haddock the Third, as he overcomes obstacles on his journey of "becoming a hero, the hard way". The books were published by Hodder Children's Books in the UK and by Little, Brown and Company in the US. The first book was published in 2003 and the 12th and final one in 2015. By 2015, the series had sold more than seven million copies around the world. The books have subsequently been adapted into a media franchise consisting of three animated feature films, several television series and other media, all produced by DreamWorks Animation.

Cressida Cowell FRSL is a British children's author, popularly known for the book series, How to Train Your Dragon, which has subsequently become an award-winning film franchise as adapted by DreamWorks Animation. As of 2015, the series has sold more than seven million copies around the world.