Olfactory binding proteins are essential components of the highly sensitive olfactory system in insects. They play crucial roles in detecting, binding, and transporting environmental odorants and pheromones to olfactory receptors. Although a large number of olfactory binding proteins have been identified in insects to date, research in this field continues to advance rapidly. This review summarizes recent progresses in understanding their structures, functions, mechanisms of action, and potential applications. Structurally, these proteins typically form simple, stable, spherical conformations composed of α-helices and/or β-sheets, which support environmental adaptability and diverse physiological functions. Two main hypotheses have been proposed to explain their mechanisms of action: pH-dependent regulation and ligand-induced conformational changes. In terms of practical applications, olfactory binding proteins have shown great promise in biological pest control, the breeding of economically important insects, and the development of biosensors, making them attractive targets for future research and innovation.