<p>Microdroplets are ubiquitous atmospheric micro-environments, including clouds, sea spray, and ambient aerosols, where interfacial physicochemical properties can drive reaction kinetics distinct from those in bulk aqueous phases. Increasing evidence suggests that microdroplets are not merely passive solvents activated by external factors such as sunlight, but may serve as autonomous interfacial microreactors capable of promoting accelerated transformations and spontaneous redox chemistry. This review synthesizes recent advances in microdroplet chemistry from an atmospheric science perspective, with emphasis on interfacial properties, reaction acceleration mechanisms, redox pathways, and analytical methodologies. We further summarize documented reactions involving organic and inorganic species to establish a theoretical foundation for understanding their role in global elemental cycles. Elucidating these interfacial processes is crucial for accurately quantifying the influence of microdroplet-mediated chemistry on atmospheric transformations and climate dynamics.</p>