Biological control agents, such as bacteria and viruses, offer viable alternatives to agrochemicals for controlling pests and diseases, playing a critical role in integrated pest management (IPM) and integrated plant protection (IPP). However, their use is not without challenges, particularly in the context of climate change. Therefore, this chapter examines how climate change affects the effectiveness of bacterial and viral biocontrol agents (BCAs). Research indicates that climate change can both enhance and diminish the efficacy of plant growth-promoting bacteria (PGPBs) and rhizobacteria (PGPRs) based on specific environmental conditions. Similarly, viral BCAs face significant challenges due to temperature fluctuations and UV radiation, which can alter their effectiveness and impact insect pest dynamics. Overall, this chapter highlights the importance of incorporating these BCAs into IPM and IPP strategies to mitigate climate change effects on agriculture, while also calling for more field-based and long-term research to address existing limitations.