Abstract: Marine fronts are critical sub-mesoscale physical processes in the estuary-coastal ocean continuum, regulating microbial diversity, distribution patterns, and ecological functions. We systematically reviewed the characteristics, formation mechanisms, and ecological effects of the sediment front, plume front, and upwelling front, focusing on how the frontal dynamic processes (e.g., convergence effect, secondary circulation, and vertical mixing) influenced the microbial community diversity, assembly processes, metabolic functions, and biogeochemical cycles by driving the environmental gradients, nutrient transport, and particulate organic matter transport pattern. Frontal physical processes provided crucial pathways and mechanical energy for planktonic microbes to acquire nutrients and sustain biological activities. The frontal convergence effect improved the light condition, significantly elevating primary productivity in the frontal zone, thereby driving microbial enrichment and nutrient cycling. The lateral transport and vertical mixing processes of frontal zones profoundly influenced microbial community distribution patterns, extracellular enzyme activity, and dispersal-fusion dynamics. In addition, we summarized the relative importance of stochastic (e.g., dispersal limitation) and deterministic processes in microbial community assembly within frontal zones, and highlighted the role of interspecies interaction in shaping community structure.