This edited volume brings together papers by both eminent and rising scholars to celebrate Saul Kripke's singular contributions to modal logic. Kripke's work on modal logic helped usher in a new semantic epoch for the field and made facility with modal logic indispensable not only to technically oriented philosophers but to theoretical computer scientists and others as well. This volume features previously unpublished work of Kripke's as well as a brief intellectual biography recounting the story of how Kripke became interested in, and made his first contributions to, modal logic. However, the majority of the volume's contributions are forward-looking, and produce new philosophical and technical insights by engaging with ideas tracing back to Kripke.