Plant bacteriology, a vital branch of plant pathology, has grown tremendously in both scope and significance over recent decades. The increasing frequency and impact of bacterial diseases on crops have posed serious threats to global food security, necessitating an in-depth understanding of the nature, behavior, and management of bacterial pathogens. “Plant Bacteriology Refresher” has been crafted with the intent of offering a concise yet comprehensive guide to students, educators, researchers, and plant health professionals who seek a firm grounding in the fundamentals of plant bacteriology along with insights into the latest advancements in the field. The book begins with an Introduction to Plant Bacteriology, setting the stage by highlighting the importance of studying plant-pathogenic bacteria in the context of sustainable agriculture and plant health. A brief History of Plant Bacteriology follows, tracing the pivotal discoveries and scientific milestones that have shaped our current understanding, from the pioneering work of scientists like T.J. Burrill and E.F. Smith to the molecular breakthroughs of modern times.