"The Worst Witch" is a children's book series written by Jill Murphy. It follows the adventures of Mildred Hubble, a young witch who struggles to fit in at Miss Cackle's Academy for Witches. Despite her clumsiness and mishaps, Mildred's kind heart and determination often lead her to save the day. The series has been adapted into various formats, including television shows and stage productions. It emphasizes themes of friendship, acceptance, and the importance of being true to oneself, making it a beloved story for young readers around the world.