Abstract: The rapid advancement of two-dimensional (2D) materials has created new opportunities for next-generation electronic, optoelectronic, and energy-related devices. Following the successful isolation of graphene, significant research efforts have focused on exploring layered materials with reduced dimensionality. However, the intrinsic zero bandgap of graphene severely limits its applicability in logic electronics and optoelectronic devices, which has prompted the search for alternative 2D semiconductors with finite and tunable bandgaps. Among the various candidates, molybdenum disulfide (MoS₂), a representative transition metal dichalcogenide, has emerged as a prototypical 2D semiconductor owing to its intrinsic bandgap, atomic-scale thickness, excellent electrostatic gate control, and strong light–matter interactions. In this review, we systematically summarize recent advances in MoS₂ materials, spanning fundamental synthesis strategies to advanced device applications. The preparation methods of MoS₂ are broadly categorized into top-down and bottom-up approaches. Top-down strategies, including mechanical exfoliation, liquid phase exfoliation, and electrochemical ion intercalation, enable the production of high-quality monolayer or few-layer MoS₂ with relatively preserved crystal structures, which are particularly suitable for fundamental studies and proof-of-concept devices. In contrast, bottom-up approaches such as chemical vapor deposition (CVD), metal organic CVD, and hydrothermal and solvothermal synthesis offer scalable routes for producing large-area films or nanostructured MoS₂ with controllable thickness, morphology, and composition. The growth mechanisms, key process parameters, and intrinsic advantages and limitations of these methods are critically discussed. The unique electronic and optical properties of MoS₂, especially its indirect-to-direct bandgap transition when thinned to a monolayer, enable a wide range of device applications. We review the state-of-the-art progress in MoS₂-based electronic and optoelectronic devices, including field-effect transistors, photodetectors, and light-emitting devices. Particular emphasis is placed on the recent advances in photodetectors, where interface engineering, strain modulation, and van der Waals heterostructures have been employed to achieve high responsivity, low dark currents, and low power consumption. Moreover, emerging research on the integration of MoS₂ with silicon photonic platforms and thin-film lithium niobate chips is highlighted, demonstrating the potential of MoS₂ for on-chip integrated optoelectronics. Beyond electronic and optoelectronic devices, the applications of MoS₂ in energy storage and conversion are comprehensively reviewed, including electrocatalytic hydrogen-evolution reactions, lithium-ion batteries, and supercapacitors. Strategies such as phase engineering, defect modulation, heterostructure construction, and composite design are summarized to elucidate how the intrinsic activity, conductivity, and structural stability of MoS₂ can be effectively enhanced. In addition, the applications of MoS₂ in chemical gas sensing, biosensing, drug delivery, photothermal therapy, and biomedical imaging are discussed, emphasizing the role of surface functionalization and nanostructure engineering in improving sensitivity, selectivity, and biocompatibility. Finally, the key challenges hindering the practical application of MoS₂ are analyzed, including wafer-scale single-crystal growth, contact resistance, environmental stability, and large-area device integration. Future research directions are proposed focusing on controllable synthesis, interface and contact optimization, stability enhancement, and system-level integration. This review aims to provide a comprehensive and timely reference for researchers working on MoS₂ and related 2D materials and facilitate their transition from laboratory-scale studies to practical applications.