The article provides a comprehensive review of negative thermal expansion (NTE) metamaterials, focusing on their design, fabrication, and applications. NTE materials, which shrink when heated, are crucial in various industries such as electronics, biomedicine, and aerospace due to their ability to mitigate thermal distortions. The review highlights the emergence of mechanically engineered NTE materials, also known as mechanical metamaterials, which exhibit NTE through their architectural design rather than material properties. Additive manufacturing techniques, particularly laser powder bed fusion (LPBF) and direct energy deposition (DED), have been successfully used to fabricate complex NTE structures. The article discusses various design methodologies, including bending-based and stretch-based architectures, and explores the challenges and advancements in material selection and fabrication processes. It also compares the microstructural properties of parts fabricated using additive manufacturing (AM) and conventional manufacturing (CM) techniques, emphasizing the importance of material compatibility and interface strength in achieving effective NTE performance. The review aims to bridge the gap in the literature by providing a state-of-the-art overview of NTE metamaterials, highlighting their potential in addressing thermal expansion issues in high-precision applications.The article provides a comprehensive review of negative thermal expansion (NTE) metamaterials, focusing on their design, fabrication, and applications. NTE materials, which shrink when heated, are crucial in various industries such as electronics, biomedicine, and aerospace due to their ability to mitigate thermal distortions. The review highlights the emergence of mechanically engineered NTE materials, also known as mechanical metamaterials, which exhibit NTE through their architectural design rather than material properties. Additive manufacturing techniques, particularly laser powder bed fusion (LPBF) and direct energy deposition (DED), have been successfully used to fabricate complex NTE structures. The article discusses various design methodologies, including bending-based and stretch-based architectures, and explores the challenges and advancements in material selection and fabrication processes. It also compares the microstructural properties of parts fabricated using additive manufacturing (AM) and conventional manufacturing (CM) techniques, emphasizing the importance of material compatibility and interface strength in achieving effective NTE performance. The review aims to bridge the gap in the literature by providing a state-of-the-art overview of NTE metamaterials, highlighting their potential in addressing thermal expansion issues in high-precision applications.