Born in New York City, John grew up in Elmhurst, Queens, studying art at Cooper Union in 1924, and at New York University in 1925.[1] He explained his choice of pseudonym as such: "Crockett is my childhood nickname. My real name is David Johnson Leisk. Leisk was too hard to pronounce -- so -- I am now Crockett Johnson!"[1] He died of lung cancer.[1]
Johnson also collaborated on four children's books with his wife, Ruth Krauss. The books were: The Carrot Seed, How to Make an Earthquake, Is This You?, and The Happy Egg.
The books Harold and the Purple Crayon, Harold's Fairy Tale, and A Picture for Harold's Room have been adapted for animation by Gene Deitch.