Paul Zindel Jr. (May 15, 1936 – March 27, 2003) was an American playwright, young adult novelist, and educator. In 1964, he wrote The Effect of Gamma Rays on Man-in-the-Moon Marigolds, his first and most successful play. The play ran off-Broadway in 1970, and on Broadway in 1971, winning the 1971 Pulitzer Prize for Drama. It was also adapted into a 1972 movie by 20th Century Fox.

Charlotte Zolotow, then a vice-president at Harper & Row (now HarperCollins), encouraged him to write for her book label. Zindel wrote 39 books, all aimed at children or young adults. Many of these were set in his hometown of Staten Island, New York, and were semi-autobiographical, focusing on teenage misfits with abusive or neglectful parents. Despite the often dark subject matter of his books, Zindel's work remained popular and influential.