This review discusses the development of nanostructured Pt-alloy catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells. The goal is to reduce the use of platinum (Pt) while maintaining or improving catalytic activity and stability. The review highlights the importance of nanostructuring, alloying, and surface engineering to achieve these objectives. Pt-alloy catalysts can be categorized into three types: (i) Pt-alloy nanoparticles, (ii) Pt-alloy nanotextures such as Pt-skins/monolayers on top of base metals, and (iii) branched or anisotropic elongated Pt or Pt-alloy nanostructures. The review discusses the effects of composition, structure, morphology, and particle size on ORR electrocatalysis, as well as the impact of post-treatments and synthesis methods on catalyst performance. It also addresses the challenges of catalyst stability, particularly the dissolution of base metals in acidic environments, and proposes strategies to improve stability, such as surface modification with Pt-skins or textured surfaces. The review concludes that nanostructured Pt-alloy catalysts offer significant advantages over traditional Pt-based catalysts in terms of activity, stability, and cost-effectiveness for PEM fuel cell applications.This review discusses the development of nanostructured Pt-alloy catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane (PEM) fuel cells. The goal is to reduce the use of platinum (Pt) while maintaining or improving catalytic activity and stability. The review highlights the importance of nanostructuring, alloying, and surface engineering to achieve these objectives. Pt-alloy catalysts can be categorized into three types: (i) Pt-alloy nanoparticles, (ii) Pt-alloy nanotextures such as Pt-skins/monolayers on top of base metals, and (iii) branched or anisotropic elongated Pt or Pt-alloy nanostructures. The review discusses the effects of composition, structure, morphology, and particle size on ORR electrocatalysis, as well as the impact of post-treatments and synthesis methods on catalyst performance. It also addresses the challenges of catalyst stability, particularly the dissolution of base metals in acidic environments, and proposes strategies to improve stability, such as surface modification with Pt-skins or textured surfaces. The review concludes that nanostructured Pt-alloy catalysts offer significant advantages over traditional Pt-based catalysts in terms of activity, stability, and cost-effectiveness for PEM fuel cell applications.