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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37. Hermione Granger
Ruby Hansford age 8 Portsmouth dressed as Hermione Granger from Harry Potter for World Book Day. Photo: Sophie Boden
38. Peter Pan and Tinkerbell
Rozalia age 6 and Roman age 4 as Tinkerbell and Peter Pan for World Book Day. Photo: Emma Susanu
39. Room on the Broom and Goldilocks
Maisie (age 6) as the Witch from Room on the Broom and Maddison (age 4) as Goldilocks, both from Rowlands Castle, for World Book Day. Photo: Josie Roach
40. 101 Dalmatians
the staff at Little Spinnakers Preschool in Milton, Portsmouth dressed up for World Book Day as characters from 101 Dalmatians. Photo: Kaz Smith