Many left their normal school uniforms at home on Thursday, March 6 and instead dressed up for the day as characters from their favourite books.
Photographer Tony Hendron took these great pictures when he popped into St John The Baptist Primary School / Bunscoil Eoin Baiste, Ballyoran Primary School, Hart Memorial Primary School and Millington Primary School.
We also asked our readers to share photos of their children dressed up in their fun costumes and we were delighted with the response. Thanks to all who shared their pictures with us.

33. World Book Day
Mollie as Rapunzel. Photo: Marissa Best

34. World Book Day
Rémi and Edison as Mario and Luigi. Photo: Kevina McKeown

35. World Book Day
Caleb age 3 all dressed up as Captain America Photo: Sarah McCausland

36. World Book Day
Kaiya as Alice in Wonderland Photo: Emma Jane

