Tomato (Solanum lycopersicum L.) is one of the world's most widely cultivated vegetable crops and remains highly vulnerable to a large number of fungal, bacterial, and viral pathogens. This paper presents a comparative review of the major diseases affecting tomato, drawing together their causal agents, symptomology, epidemiological requirements, reported yield impact, and management strategies. Fungal diseases (early blight, late blight, Fusarium wilt, Verticillium wilt, and Septoria leaf spot), bacterial diseases (bacterial wilt, bacterial spot, and bacterial canker), and viral diseases (tomato leaf curl virus, tomato mosaic virus, and tomato spotted wilt virus) are compared side by side. The comparison shows that while foliar fungal blights are primarily weather-driven, vascular wilts (fungal and bacterial) are soil-borne and persist for years, and viral diseases depend almost entirely on insect vectors for spread. An integrated, disease-category-specific management approach is recommended over uniform, blanket control measures.