Coastal Bangladesh, home to approximately 70 million people and contributing nearly 40% of the national rice area, faces converging climate hazards—warming, erratic monsoon rainfall, and salinity intrusion—that are reshaping rice disease epidemiology. Following the PRISMA 2020 guidelines, this structured critical review synthesizes 64 eligible sources (2020–2026; enumerated in Supplementary Table S3) to investigate why coastal rice diseases are intensifying, identify the climate variables influencing specific pathogens, and evaluate existing interventions. Three principal findings emerge, each stated at the level of confidence its evidence supports. First, coastal temperature and relative humidity are reported to rise at approximately 0.04 °C and 0.14% per year (1981–2018), and sheath blight (Rhizoctonia solani) has been reported to increase more rapidly than blast (Magnaporthe oryzae) and bacterial leaf blight (Xanthomonas oryzae pv. oryzae)—a finding resting on a single long-term series (Level 2). Second, salinity and flooding are associated with host-defense suppression: salinity degrades 20–30% of coastal rice production and, in experimental and survey evidence, is linked to weakened host resistance, while a week of complete submergence kills most rice plants; the salinity × pathogen interaction in Bangladesh fields remains unquantified and is treated as a hypothesis (Level 3). Third, the intervention landscape is fragmented: forecasting achieves high accuracy under controlled validation yet reaches few coastal farmers; early warning remains unvalidated for the aus–aman–boro calendar; and no integrated package combining salinity mitigation with pathogen management has been tested. We conclude with an explicit evidence-grading rubric, ten prioritized research gaps, and a decision-ready agenda for coastal smallholders