Jonathan Tweet (born 1965) is an American game designer who has been involved in the development of the role-playing games Ars Magica, Everway, Over the Edge, Talislanta, the third edition of Dungeons & Dragons and 13th Age, and the collectible miniatures game Dreamblade. In 2015 Tweet released Grandmother Fish, a full-color, full-sized book about evolution aimed at preschoolers. In 2018 Tweet released Clades and Clades Prehistoric, two card games for children and adults which demonstrate the concept of a clade.