Who is the youngest author to publish a book?

As of 2015, the youngest published author in the world is Dorothy Straight. Straight was 4 years old when she wrote the book "How the World Began" in 1962. The book was published 2 years later when Straight was 6.

"How the World Began" is a children's book written and illustrated by Straight. She was inspired to write the story after participating in a play put on by her pre-kindergarten class and created the book as a gift for her grandmother. The book is an interpretation of the Biblical creation myth, beginning with God's creation of animals and plants and progressing through the invention of mundane items like needles and thread.