Producing pure substances has been the obsession of scientists for centuries and has defined chemistry as we know it. Nowadays, most of our economy still relies on the chemist ability to extract and purify metallic elements from raw or recycled materials, which, in most cases, is done partly or entirely via hydrometallurgical methods. Here, the authors present the critical aspects of this relatively overlooked, yet critical, chemistry discipline. This review article highlights the importance of hydrometallurgical processes for strategic industrial sectors, put in perspective traditional separation methods with emerging ones (new metal-binding chelators, ionic liquids, deep eutectic solvents, microfluidic devices, biomaterials, etc.), critically reviews progress made on separation methods over the past two decades, and highlights the challenges lying ahead for the hydrometallurgists in academia and the industry.