Catherine "Kate" Klise (born 1963) is an American author of children's literature. Many of her books are illustrated by her sister, M. Sarah Klise. Their popular Regarding series is presented in a scrapbook style format, with letters, journal entries, and related ephemera telling the story. She is also known for her picture books as well as the bestselling 43 Old Cemetery Road series. Kate Klise's first adult novel, In the Bag, was released in 2012.