World Book Day Costumes World Book Day is all about sharing a love of stories, and our World Book Day costumes help bring books to life for everyone involved. Whether it’s a child dressing up as a favourite character or a teacher joining in for a classroom theme, you’ll find fun, comfortable outfits made for a full day at school. Our range includes easy-to-wear children’s fancy dress for boys and girls, along with simple Fancy Dress Accessories to complete the look without hassle. With fast UK delivery, easy returns, and a secure checkout, parents and teachers can plan ahead with confidence and enjoy a stress-free World Book Day filled with imagination.