Cyanobacterial blooms are increasingly frequent and severe in freshwater ecosystems worldwide, driven by multiple climate-change-related factors. Rising global temperatures, altered precipitation patterns, prolonged water stratification, and elevated atmospheric CO₂ have created conditions that strongly favor bloom-forming cyanobacteria. These changes have not only enhanced bloom frequency and duration but also facilitated the expansion of blooms into previously unaffected geographic areas, including oligotrophic lakes, high-altitude regions, and polar ecosystems. Cyanobacteria possess adaptive traits such as thermal tolerance, nitrogen fixation, and allelopathic capabilities that allow them to dominate over other phytoplankton groups under these changing conditions. This chapter explores the complex interplay between climatic variables and bloom dynamics, emphasizing physiological responses, ecological shifts, and the resulting risks to ecosystem health, biodiversity, and human well-being. The chapter also examines emerging monitoring technologies, such as remote sensing and predictive modeling, alongside mitigation strategies like nutrient load reduction, hydrological control, and adaptive water resource management. Public health risks from cyanotoxins, economic losses due to water quality degradation, and the need for interdisciplinary, climate-resilient management approaches are critically discussed. As climate pressures mount, the understanding of cyanobacteria’s response to environmental drivers becomes essential. Integrated strategies that combine science, community engagement, and policy are key to minimizing bloom impacts and ensuring the sustainability of freshwater ecosystems.