Teachers and children in Littlehampton have been dressing up, with costumes including Gangsta Granny, Horrid Henry, Heather from the Rainbow Magic collection, Dorothy and the Scarecrow from The Wizard of Oz and Paddington Bear.
Gem Rowland, who sent in a photo of nine-year-old Ivy, said: "My daughter's school had a vocabulary parade, so they went dressed as words. Ivy was affirmations."
Sarah Fletcher had to be inventive for her little Oompa Loompa. She said: "Her wig never came in time but we made do."
Helen Donovan sent in a picture of Gangsta Granny and said: "She loves his books. This book did make her cry, the ending was sad."
1. World Book Day
Helen Donovan sent in this picture of Gangsta Granny. She said: "She loves his books. This book did make her cry, the ending was sad." Photo: Helen Donovan
2. World Book Day
Tash Spencer sent in this picture of Arthur, five, as Harry Potter and William, two, as Chase Photo: Tash Spencer
3. World Book Day
Sam Dorey sent in this picture of nine-year-old Archie Dorey as Messi, with the book that inspired him Photo: Sam Dorey
4. World Book Day
Aimiee Winter sent in this picture of four-year-old Levi dressed as Horrid Henry Photo: Aimiee Winter