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.

49. World Book Day
The very hungry caterpillar! Photo: Kerrie Hall

50. World Book Day
All dressed up on World Book Day. Photo: Jodie Covington

51. World Book Day
Aubree as ‘Peppa loves doctors and nurses'. Photo: Shereen Donaldson

52. World Book Day
Righnach as a firefighter. Photo: Clare Hughes

