Logic deals with the fundamental notions of truth and falsity. Modal logic arose from the philosophical study of "modes of truth" with the two most common modes being "necessarily true" and "possibly true". Research in modal logic now spans philosophy, computer science, and mathematics, using techniques from relational structures, universal algebra, topology, and proof theory. These proceedings record the papers presented at the 2018 conference on Advances in Modal Logic, a biennial conference series with the aim of reporting important new developments in pure and applied modal logic. The topics include decidability and complexity results, proof theory, model theory, interpolation, as well as other related problems in algebraic logic.