It's the 18th time the Smarties award has happened - with past winners including JK Rowling.
There were also winners and runners-up in other ages categories.
Here's the full list:
5 and Under
Gold Medal
Jazzy in the Jungle by Lucy Cousins
Silver Medal
Pizza Kittens by Charlotte Voake
Bronze Medal
Oscar and Arabella by Neal Layton
6-8 Age Category
Gold Medal
That Pesky Rat by Lauren Child
Silver Medal
Pirate Diary- The Journal of Jake Carpenter by Richard Platt and illustrated by Chris Riddell
Bronze Medal
The Last Wolf by Michael Morpurgo, illustrated by Michael Foreman
9-11 Age Category
Gold Medal
Mortal Engines by Philip Reeve
Silver Medal
Cold Tom by Sally Prue
Bronze Medal
Stop the Train by Geraldine McCaughrean
Kids Club Network Category
That Pesky Rat, by Lauren Child