Supercritical fluid extraction (SFE) is a core research area in the Laboratory for Strategic Materials, where we develop advanced separation technologies for the recovery of critical and strategic elements from both primary and secondary resources. Using supercritical fluids—most commonly supercritical CO₂—often in combination with tailored ligands and modifiers, we enable selective, efficient, and environmentally responsible extraction of valuable metals. Our work has demonstrated the recovery of rare earth elements (REEs) from complex secondary materials including NiMH batteries, NdFeB permanent magnets, and fluorescent lamps, as well as the extraction of Li, Ni, Co, and Mn from NMC lithium-ion batteries. In addition to urban mining, we apply SFE to primary resources, including the extraction of REEs from zircon ore concentrates and scandium and REEs from other mineral concentrates. These efforts highlight the versatility of SFE as a low-waste, tunable platform for critical materials recovery and support the development of sustainable supply chains for advanced energy and manufacturing technologies.