Extremophiles exhibit remarkable adaptations that enable survival in harsh environments, among which acidophiles have some industrial potential. Acidophiles thrive in low-pH environments and possess unique metabolic and enzymatic traits with high industrial relevance. Their ability to oxidize iron and sulfur compounds forms the basis of bioleaching, a technology applied to recover valuable metals from sulfide ores and increasingly from electronic waste. Heap leaching has been widely used for large-scale copper recovery, while tank leaching enables controlled processing of gold, nickel, and other metals. In recent years, bioleaching has expanded beyond natural ores to “urban mines,” offering sustainable solutions for recycling critical elements such as cobalt, rare earths, and lithium from electronic waste. These developments demonstrate the versatility of acidophiles in supporting both primary and secondary resource recovery. Despite these advances, the application of bioleaching to marine mineral resources remains limited. Current acidophiles often fail to tolerate high salinity, underscoring the need to discover and characterize marine-adapted iron- and sulfur-oxidizers. Future progress will depend on integrating microbiology, biotechnology, and environmental considerations to expand biohydrometallurgy while minimizing ecological impact.