We asked readers of the Lancashire to share their little one's fabulous costumes and they did not disappoint.
In fact we received so many great pictures - over 300 - that we have had to make multiple photo galleries to show them all off.
9. World Book Day 9
L: Oliver age 4 as Toothless out of How to Train your Dragon. R: Albie-Jon age 7 as Where's Wally with his friend Harry Potter. | submit
10. World Book Day 10
L: Callie, age 6, as Where's Wally. R: Lucy aged 8 as Ruby from Ruby's Worry and Emma aged 6 as a pirate. | submit
12. World Book Day 12
L: Teddie aged 7 Dog Man. R: Erin as Alice & Daisy as Matilda | submit
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