The biosphere hosts a vast diversity of organisms, including more than 155,000 described fungal species, of which thousands are recognized as entomopathogenic fungi. These fungi possess unique mechanisms that allow them to overcome host immune defenses, often through the production of specialized compounds known as mycotoxins. Mycotoxins have promising applications in biological control as well as in medicine and pharmacies. However, effective utilization requires comprehensive knowledge of their properties. This chapter reviews several notable mycotoxins, such as beauvericin, bassiatin, beauverolides, brevianamide, cyclosporin, myriocin, destruxins, efrapeptins, enniatin, fumonisins, fusarin, iso-isariin, lateritin, leucinostatins, metarhizin A, oosporein, pentostatin, rhizoferrin, swainsonine, and trichothecenes that are derived from commonly occurring entomopathogenic fungi. We highlight recent advances in understanding their diversity, bioactivity, biosynthetic pathways, mechanisms of action, detection techniques, detoxification strategies, and potential applications in agriculture and medicine. The findings presented aim to offer a comprehensive overview of the mycotoxins produced by entomopathogenic fungi and their diverse significance.