Additive manufacturing (AM), also known as 3D printing, is a transformative technology used to fabricate complex components by adding material layer by layer. It offers precise control and customization, making it a preferred choice in various industries, including aerospace. This review discusses the application of AM in aerospace, covering design, methods, processes, materials, testing, standards, certification, and training. AM allows for the creation of lightweight, high-performance components, which is crucial for aerospace applications. The review outlines the end-to-end process of AM, from design to finished product, and highlights the importance of topology optimization in reducing weight while maintaining performance. Various AM techniques, such as stereolithography, fused deposition modeling, direct energy deposition, and powder bed fusion, are discussed, along with their applications in aerospace. The review also addresses the challenges of AM in aerospace, including material certification, process control, and post-processing. Materials used in aerospace AM include titanium alloys, nickel-based superalloys, and composites, which are chosen for their strength, heat resistance, and other properties. Testing and certification are essential to ensure the quality and safety of AM components. The review emphasizes the need for training and education in AM to meet the growing demand in the aerospace industry. Overall, AM is a key technology in aerospace, offering innovative solutions to complex engineering challenges and enabling the production of lightweight, high-performance components. However, challenges such as material limitations, cost, and quality control must be addressed for widespread adoption. The review concludes that AM is a major industrial revolution in the aerospace sector, with ongoing research and development aimed at improving its capabilities and applications.Additive manufacturing (AM), also known as 3D printing, is a transformative technology used to fabricate complex components by adding material layer by layer. It offers precise control and customization, making it a preferred choice in various industries, including aerospace. This review discusses the application of AM in aerospace, covering design, methods, processes, materials, testing, standards, certification, and training. AM allows for the creation of lightweight, high-performance components, which is crucial for aerospace applications. The review outlines the end-to-end process of AM, from design to finished product, and highlights the importance of topology optimization in reducing weight while maintaining performance. Various AM techniques, such as stereolithography, fused deposition modeling, direct energy deposition, and powder bed fusion, are discussed, along with their applications in aerospace. The review also addresses the challenges of AM in aerospace, including material certification, process control, and post-processing. Materials used in aerospace AM include titanium alloys, nickel-based superalloys, and composites, which are chosen for their strength, heat resistance, and other properties. Testing and certification are essential to ensure the quality and safety of AM components. The review emphasizes the need for training and education in AM to meet the growing demand in the aerospace industry. Overall, AM is a key technology in aerospace, offering innovative solutions to complex engineering challenges and enabling the production of lightweight, high-performance components. However, challenges such as material limitations, cost, and quality control must be addressed for widespread adoption. The review concludes that AM is a major industrial revolution in the aerospace sector, with ongoing research and development aimed at improving its capabilities and applications.