We asked readers of the Lancashire to share their little one's fabulous costumes and they did not disappoint.
In fact we received so many great pictures - over 300 - that we have had to make multiple photo galleries to show them all off.
You can see part one of the World Book Day gallery here and part two here but look below at even more of the amazing costumes from across Lancashire...
1. World Book Day 1
L: Isla-Rae age 7 & Aida-Jayne age 3 dressed up as Wilma Flintstone. R: Lucca aged 3 as Elmer. | submit
2. World Book Day 2
L: Archie Lee, age 4 as Dragon of the day. R: Vincent, 3, as The Gingerbread Man. | submit
3. World Book Day 3
L: Esmeè, age 7, from The Day the Crayons Quit. R: Scarlett, age 4, as Princess Belle age 4 & Hudson, 2, as Batman. | submit
4. World Book Day 4
L: Destiny aged 11 as Wednesday Adams. R: Ivy age 4 as Winnie the Pooh. | submit