And you were all good enough to share your pictures with us, thanks! Here's some of our favourites…
13. World Book Day 47. Alfie Lamb aged 10. Dressed as David Attenborough
World Book Day 47. Alfie Lamb aged 10. Dressed as David Attenborough Photo: submit
14. World Book Day 48. Louie as Dobby the House Elf in Harry Potter and Hugo and Nico as Red and Orange Crayon from The Day the Crayons Quit.
World Book Day 48. Louie as Dobby the House Elf in Harry Potter and Hugo and Nico as Red and Orange Crayon from The Day the Crayons Quit. Photo: submit
15. World Book Day 49. Georgie age seven as Trixie from Call the midwife.
World Book Day 49. Georgie age seven as Trixie from Call the midwife. Photo: submit