In the past 13 years since the publication of Longwall Mining, 2nd edition in 2006, although there have been no major changes in longwall mining technology and operations, many incremental developments in the whole system as well as various subsystems of the existing longwall mining operational technologies as detailed in the 2nd edition have been added to this edition. Major developments are automation, and health and safety technology, as well as equipment reliability, thereby greatly increasing productivity and cutting cost. In particular, the longwall system can now run automatically cut by cut forever without operators' intervention provided that the geology allows it. Other health and safety features such as LASC, personal proximity detection, color lighting, automatic shield water sprays and remote shearer control are fully operational. There are more than 7000 sensors installed in current longwall mining systems. The big data obtained and fast communication technology have been fully utilized to improve and solve operational problems in real time. Those features are fully documented in the new edition. In pursuit of high productivity and cutting cost, life cycle management that increases equipment reliability has been implemented by OEM. Automation improvement such as tail-end automatic chain tensioner greatly extends AFC chain's service life. Other incremental improvements including dust and methane controls, entry development, panel design and face move are addressed. Additional operational issues such as extension of panel width and compatibility test are also discussed. Since the last plow longwall mine was closed in 2018, the chapter on plow longwalling has been dropped and in its place Automation of Longwall Components and System is added. Also, a new chapter Longwall Top Coal Caving Mining (LTCC) is added due to its successful application in Australia since 2005. Longwall Mining, 3rd edition will be of interest to professionals and academics in the field of mining engineering specifically, serving both as a reference work and an (under)graduate textbook, but will also interest civil, geomechanical and geological engineers and rock mechanics professionals, as well as coal operators, mining consultants, researchers, equipment manufacturers, and government regulators.