Beneficial insects contribute significantly to sustainable agriculture through the provision of necessary ecosystem services, including pollination, natural pest control, cycling of soil nutrients, and production of high-value commodities. This chapter discusses beneficial insect classification, diversity, ecological functions, and economic value, and highlights their role in food and environmental sustainability. Pollinators such as bees and butterflies, natural predators such as parasitoid wasps and beetles, and decomposers such as dung beetles and termites boost crop productivity and ecosystem resilience. Unfortunately, their populations are under growing pressure due to the excessive use of pesticides, habitat destruction, and climate change, resulting in lower ecological stability and increased reliance on artificial inputs. This chapter addresses integrated approaches, such as habitat management, organic agriculture, microbial fermentation, and integrated pest management (IPM), to preserve and promote beneficial insects in agroecosystems. It also presents novel approaches, such as biotechnological tools, mass rearing, and citizen science engagement, for the long-term resilience of agricultural systems. Conservation and promotion of beneficial insects are not only critical for agricultural productivity but also for the success of global sustainability targets.