Microbial communities have been a vital part of Earth’s history, shaping the course of evolution and influencing environmental conditions. Microorganisms have evolved diverse adaptations to thrive in unpredictable habitats, where fluctuating factors such as pH, competition, and resource availability pose constant challenges. Metabolism, at the core of cellular activity, integrates external cues into intracellular signaling processes, regulating cellular responses. Microbes’ survival is profoundly impacted by their habitats, and they must adapt to changing conditions like extreme temperatures, pressure, and nutrient availability. Recent advances in biotechnology and bioinformatics have deepened our understanding of microorganisms, revealing their pivotal roles in various ecosystems and their potential applications in fields like biotechnology, agriculture, and environmental science. Secondary metabolites, produced by certain bacteria, include natural antibiotics that target essential cellular processes and play various roles in ecological interactions, differentiation, and defense. Analyzing bacterial secondary metabolism within its ecological context reveals novel pathways and enzyme substrate availability. Extremophiles, microorganisms thriving in extreme environments, offer a treasure trove of bioactive secondary metabolites. They have attracted attention due to their diverse medicinal properties, including antibacterial, antiviral, anticancer, and anti-inflammatory effects. Extremozymes, enzymes derived from extremophiles, have revolutionized various industries, offering stability and efficiency under extreme conditions. Extremophiles continue to be explored for their biotechnological potential, from biocatalysis to biotransformation processes. Notably, alkalophilic fungi from extreme environments have been found to produce antimicrobial peptides, shedding light on novel bioactive compounds. The world’s increasing demand for novel bioactive compounds to combat antibiotic resistance and other medical challenges underscores the importance of exploring extremophiles and their metabolites. Natural compounds, including those derived from extremophilic microorganisms, represent a valuable source for developing new therapeutic agents in fields such as antimicrobial, antibiofilm, antitumor, and anticancer drugs. This chapter provides a comprehensive overview of peptides and metabolites from extremophilic microbes and their diverse biological applications, highlighting their potential to address pressing global health and industrial challenges.