Insects are threatened by multiple factors, invariably acting in synergy. Changes in land use result in habitat loss, degradation, and fragmentation, and are arguably the main current threat to insects. Freshwater communities are particularly affected by natural system modifications, such as changes in flow regimes. Climate change may be surpassing habitat destruction in importance, being a global threat affecting all species. Pollution, especially in the form of pesticides and other chemicals, but also light, sound, or effluents affecting freshwater systems and caves, is relevant in many regions under intensive human use. Invasive species are present nearly everywhere and growing in importance, as global trade increases and are especially disruptive of oceanic island and or other island-like biotas. Overexploitation could be considered a minor threat but relevant for species that are collected or traded for different purposes or are impacted by secondary effects (e.g., overexploitation of the host plant). Co-extinctions affect species dependent on others, from mammal parasites to insect parasitoids. Insect declines and extinctions lead to the loss of ecosystem services with implications for human well-being. To avoid further losses, all these threats must be urgently addressed through science-based policy changes and integrative conservation measures.