The application of microbial biopesticides as an environmentally friendly substitute for chemical pesticides in crop protection is covered in length in this chapter. Microbial pesticides consist of bacteria, fungi, viruses, nematodes, and protozoa that are used to control several diseases in food crops across the globe. The use of biopesticides as an eco-benign approach in pest management is gaining traction due to their multiple modes of action, including regulating gastrointestinal disturbance, disrupting pest growth and metabolism, activating target-poisoning mechanisms, demonstrating multisite inhibitory effects, and releasing neuromuscular toxins and bioactive substances. The chapter starts by stating that food security and environmental safety are not mutually exclusive, thus a need to devise eco-friendly ways to ensure food security via crop protection without jeopardizing environmental safety is imperative. The chapter then comprehensively discusses microbial biopesticides (bacteria, fungi, viruses, nematodes, and protozoa), their mode of action, infectivity range, and their strengths and limitations as biocontrol agents. The last part of the chapter examines issues associated with the field application of microbial biopesticides and offers some recommendations that could enhance its acceptability, usage, and performance.