This book provides a comprehensive, informative overview of the history, contemporary state, and future direction of Korean dialectological research. It covers the pre-modern attestation of awareness about linguistic variation on the Korean Peninsula, traditional dialectology in 20th century Korea, and cutting-edge analyses enabled by 21st century computer technology and informed by contemporary sociolinguistics. As well as incorporating topics and approaches that widen the discipline, the book includes new, never-before-published cartographic visualisations of early Korean dialect data and findings. This book is essential reading if you intend to engage with the study of variation in the Korean language.