The cosmetic industry’s growing shift toward sustainable alternatives to synthetic dyes has spotlighted microbial pigments, with pyomelanin emerging as a highly promising multifunctional candidate. Synthesized through the oxidative polymerization of homogentisic acid (HGA) by Pseudomonas and related species, pyomelanin is a nitrogen-free melanin that exhibits unique physicochemical properties, including water solubility, broad-spectrum ultra-violet (UV) absorbance, and robust antioxidant activity. This chapter elucidates the biosynthetic pathway of pyomelanin via HGA accumulation, highlighting key genetic regulations—such as hmgAknockout and hppD overexpression—and environmental factors like light exposure and oxidative stress that enhance production. Industrial-scale fermentation approaches, utilizing engineered microbial strains to achieve high yields, are also discussed. Owing to its dual function as a photostable pigment and redox-active metal chelator, pyomelanin offers solutions to formulation challenges in sunscreens and antioxidant-rich cosmetics, outperforming hydrophobic counterparts such as violacein and carotenoids. Furthermore, regulatory considerations and CRISPR-mediated pathway optimization strategies emphasized its potential for sustainable, high-performance cosmetic applications. By integrating microbial biosynthesis with precision engineering, pyomelanin represents a paradigm shift toward eco-friendly, multifunctional colorants in the modern skincare industry.