The day is an annual charity event held on the first Thursday of March every year to provide every child in full-time education with a voucher to be spent on a book of their choosing.
World Book Day aims to encourage reading for pleasure amongst children and is promoted in more than 100 countries around the globe.
Schools often ask both pupils and teachers dress as their favourite book characters.
The Derbyshire Times asked readers to send in pictures of their World Book Day costumes.
Below are just some of the photos we were sent of children dressed as their favourite characters.
For more of your fantastic photos click here
Also look out for a schools gallery later – as our photographer has been out and about visiting schools across Derbyshire.
1. World Book Day
Children across Derbyshire went to school dressed as their favourite characters to mark World Book Day. Photo: submit
2. Very cute!
Kate Bodell submitted this photo of Maeve as the Mouse from The Gruffalo! Photo: Kate Bodell
3. Peter Pan
Julie Sinclair Rule sent in this photo of her grandson Theo, all ready for World Book Day at nursery.💗 Photo: Julie Sinclair Rule
4. Little Red Riding Hood
Ayla aged 2, looks lovely as Little Red Riding Hood. Photo: Rebecca Cordery