This book summarizes and records the recent notable advances in diverse topics in organic crystal chemistry, which has made substantial progress along with the rapid development of a variety of analysis and measurement techniques for solid organic materials. This volume follows previously published volumes that are prepared periodically, at least every 5 years, with contributions by prominent authors in Japan and from abroad. The first volume was published in 2015, which systematically summarized the remarkable progress in assorted topics of organic crystal chemistry using organic solids and organic&inorganic hybrid materials. The second volume, published in 2020, presented advances in organic solid-state chemistry mainly from 2016 to 2020. The present volume also shows the progress of organic solid-state, especially focusing on crystalline functional materials with mechanical, luminescent, electrical and magnetic properties that have been achieved mainly in the last 5 years or so. The topics that this book dealt with, which have been rapidly developed in the last decade, will be of interest not only to researchers of organic crystals but also to those in photochemistry, materials chemistry molecular science and applied physics.