We have been inundated with a wealth of fantastic photos after putting out an appeal for them on Facebook.
This gallery has been updated throughout the day as more and more pictures have been sent over!
MORE: Best World Book Day photos from 2021, World Book Day excitement grips Portsmouth as children become their favourite superheroes
Unfortunately due to the overwhelming amount of photos we were sent and time constraints, we have not been able to feature every single one sent to us today – despite hoping to be able to do so.
But we tried to feature as many as possible - and there are over 50 images in our gallery!
The gallery is at the bottom of this article – and make sure to click through all the pages!
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29. Harry Potter
Reggie New, Age 6, from Emsworth went dressed as Harry Potter for World Book Day. Photo: Abbie Amber
30. Hermione
Mia, 7, dressed as Hermione from the Harry Potter books for World Book Day. Photo: Anna Bell
31. Jemima puddleduck
Beatrice Baker Aged 4 from Copnor dressed as Jemima puddleduck to go to College Park Infant School on World Book Day Photo: Ella Alexandra Baker
32. War of the Worlds
Morgan aged 5 from Copnor dressed as a Martian complete with a Martian tripod from HG Wells War of the Worlds for World Book Day. Photo: Charlotte Crotty