This review provides a comprehensive overview of recent advances in electrocatalysis for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). It focuses on low- and non-platinum electrocatalysts, including advanced platinum alloys, core-shell structures, palladium-based catalysts, metal oxides and chalcogenides, carbon-based non-noble metal catalysts, and metal-free catalysts. The correlation between catalyst activity and its shape, size, composition, and synthesis method is discussed. The performance and stability of carbon-based materials in fuel cells are compared with platinum, and research directions for more active and less expensive electrocatalysts are provided. The review highlights the development of novel ORR electrocatalysts with novel structures and compositions, emphasizing the importance of understanding the underlying mechanisms to improve fuel cell performance.This review provides a comprehensive overview of recent advances in electrocatalysis for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). It focuses on low- and non-platinum electrocatalysts, including advanced platinum alloys, core-shell structures, palladium-based catalysts, metal oxides and chalcogenides, carbon-based non-noble metal catalysts, and metal-free catalysts. The correlation between catalyst activity and its shape, size, composition, and synthesis method is discussed. The performance and stability of carbon-based materials in fuel cells are compared with platinum, and research directions for more active and less expensive electrocatalysts are provided. The review highlights the development of novel ORR electrocatalysts with novel structures and compositions, emphasizing the importance of understanding the underlying mechanisms to improve fuel cell performance.