Paul O. Zelinsky is an American illustrator and writer best known for illustrating children's picture books. He won the 1998 Caldecott Medal for U.S. picture book illustration, for Rapunzel. His most popular work is Wheels On the Bus, a best-selling movable book.
Zelinsky had been runner-up for the Caldecott Medal in 1985, 1987, and 1995, the latter for Swamp Angel by Anne Isaacs. Twenty years later, they were joint runners-up for the Phoenix Picture Book Award from the Children's Literature Association, which annually recognizes the best picture book that did not win a major award 20 years earlier. "Books are considered not only for the quality of their illustrations, but for the way pictures and text work together."