Abstract: Materials are the building blocks of various functional applications. With Moore’s Law approaching Si’s physical limits, traditional semiconductor-based monolithic three-dimensional (M3D) integrated circuits always suffer from the issues, including electrical performance (carrier scattering), chip-overheating (low heat conductivity), electromagnetic interference. Recently, two-dimensional transition metal dichalcogenides (2D TMDs) inherit the atomically-thin thickness of 2D materials and exhibit outstanding natures, such as smooth flatness (excellent compatibility), electronic property (thickness below 1 nm), absence of dangling bonds (decreasing carrier scattering), making them highly promising for next-generation functional devices in comparison with traditional bulk materials. Up to now, 2D TMD-based transistors have already exhibited the feasibility of replacing conventional one in terms of performances. Furthermore, the technology of large-area 2D TMDs films has been greatly successful, which lays the foundation for the fabrication of scalable 2D TMD-based devices. Besides, the scalable devices based on 2D TMDs also show the prospects of realizing ultra-high-density M3D integrated circuits owing to the presence of outstanding compatibility. Herein, we focus some thriving research areas and provide a systematic review of recent advances in the field of scalable electronic and optoelectronic devices based on 2D TMDs, including large-area synthesis, property modulation, large-scale device applications, and multifunctional device integration. The research in 2D TMDs has clearly exhibited the tremendous promise for scalable diversified applications. In addition, scalable 2D TMD-based devices in terms of mass production, controllability, reproducibility, and low-cost have also been highlighted, showing the importance and benefits in modern industry. Finally, we summarize the remaining challenges and discuss the future directions of scalable 2D TMDs devices.