Smith was born in Tulsa, Oklahoma, but moved to Corona, California at a young age. He spent summers in Tulsa, however, and cites experiences there as inspirations for his work, saying that "[o]nce you've seen a 100-foot cement buffalo on top of a donut-stand (sic) in the middle of nowhere, you're never the same."

He studied art in college at the encouragement of his high school art teacher, helping to pay for it by working as a janitor at Disneyland. He graduated with a Bachelor of Fine Arts in illustration, and moved to New York City, where he was hired to do illustrations for various publications including Time, Mother Jones, and Ms..

Smith is married to Molly Leach, who is a book designer and designed the Smith/Scieszka collaboration

Smith is most noted for his work on children's books. He is best known for his multiple collaborations with author Jon Scieszka. The two have teamed up on books such as The Stinky Cheese Man, which was considered a New York Times "Best Illustrated Book", and The True Story of the Three Little Pigs. Smith also illustrated a number of volumes of Scieszka's The Time Warp Trio novels.

Smith has also authored and illustrated his own books. He released Pinocchio: The Boy in 2002, and released John, Paul, George, and Ben in April 2006.

Smith's artistic talents have also been featured in other books and mediums. He illustrated one edition of Roald Dahl's James and the Giant Peach, and was also art director for the 1996 movie adaptation. He was also in charge of conceptual designs for Disney and Pixar's Monsters, Inc. and the film adaptation of How the Grinch Stole Christmas!.

Smith has authored and illustrated a number of books for a variety of publishing houses. Due to new editions, publishing dates may not be completely accurate.

Authored and illustrated

• Glasses - Viking Children's - 1991
• The Big Pets - Viking Children's - 1991
• The Happy Hocky Family! - Viking Children's - 1993
• Flying Jake - Viking Children's - 1996
• The Boy - Viking Children's - 2002
• The Happy Hocky Family Moves to the Country! - Viking Children's - 2003
• John, Paul, George, and Ben - Hyperion Press - 2006
• Madam President- Viking Children's - 2008
• The Big Elephant In The Room- Hyperion Press- 2008

Collaborations with Jon Scieszka

• The True Story of the Three Little Pigs - Viking Children's - 1989
• The Stinky Cheese Man - Viking Children's - 1992
• Math Curse - Viking Children's - 1995
• Squids Will Be Squids - Viking Children's - 1998
• Baloney - Viking Children's - 2001
• Science Verse - Viking Children's - 2004

• Seen Art?- Viking Childrens'- 1995

Smith has also illustrated a number of titles from Scieszka's The Time Warp Trio series of novels.

Other illustrations

• Halloween ABC - Eve Merriam - Simon & Schuster - 1987
• James and the Giant Peach - Roald Dahl - Random House - 1996 edition
• The illustrations also appear in the 1997 hardcover book The Roald Dahl Treasury.
• Hooray for Diffendoofer Day! - Dr. Seuss, Jack Prelutsky - Random House - 1998
• The Very Persistent Gappers of Frip - George Saunders - McSweeney's Publishing - 2006
• Unmentionable!-Paul Jennings Viking Penguin Inc-1999