Plant proteases are enzymes that play a critical role in various plant physiological processes, including resistance responses to biotic stresses. In legumes, the presence of proteases has been shown to modulate the resistance response to insect-pests. These enzymes have been shown to be involved in the regulation of defence mechanisms such as phytohormone synthesis, cell wall reinforcement, and the production of defence-related compounds. Moreover, the manipulation of protease activity through genetic engineering or chemical modulation has been shown to influence the susceptibility of legumes to insect-pest damage. Harnessing the potential of plant protease inhibitors offers environmentally friendly alternatives to synthetic pesticides, contributing to the sustainability of agricultural systems. This chapter underscores the importance of understanding plant-insect interactions and the mechanisms underlying resistance to effectively leverage protease inhibitors for enhancing legume crop productivity and ensuring food security in a rapidly changing world.