<p>Biopesticides constitute a category of natural products and organisms effective against pests. Given their advantages, such as easier clearance and degradation compared to chemical pesticides, along with their lack of detrimental effects on ecosystem health, they represent a promising alternative for sustainable pest management and crop protection. The development of natural biopesticides to substitute synthetic pesticides is therefore of paramount importance for securing food safety and advancing agricultural production. Monoterpenes, primarily present in plant volatile oils, are characterized by a strong aroma and a range of biological activities-including insecticidal, antimicrobial, antiviral, anti-inflammatory, antioxidant, antitumor, and anticancer effects. This profile renders them a promising platform for the research and development of new, more effective pesticides. This article reviews the biosynthetic pathways of monoterpenes and contemporary engineering strategies for their microbial synthesis. Additionally, an evolutionary analysis database for monoterpene synthases (MTPS) has been established. Finally, the biological activities of monoterpenes are summarized and analyzed, with particular emphasis on their potential and advantages as biopesticides, thereby providing direction for the future development of monoterpene-based biopesticides.</p> Graphical Abstract <p></p>