J. Otto Seibold grew up in the small town of Martinez, California. As a child, he loved to draw, and he credits Lego and the cartoons Ultraman and Speed Racer as definitive influences on his later career. High school drafting classes led to work after graduation with big corporations in the area. He was working for Clorox when he first got the idea to try illustrating for a living — his first solo design-and-illustration work was that year's company Christmas calendar.
In 1988, Seibold set off for Spain with a good friend, Vivian Walsh. Though they intended to rent a house and work on art and writing, respectively, they instead traveled through much of Europe, ran out of money, and fell in love. They moved back to San Francisco, where Seibold began doing commercial art in earnest. It was while flying across the country with their pampered dog, Dexter Lunch, that Walsh came up with the idea for their first children's picture book, Mr. Lunch Takes a Plane Ride.
J. Otto Seibold and Vivian Walsh now live in San Francisco with their three children. Their second dog has since joined Mr. Lunch in children's book fame: she stars in Olive, the Other Reindeer.