ABSTRACT Advanced materials for energy conversion and storage are central to clean and reliable energy research. Herein, three-dimensional (3D) architectures composed of MoS2-graphene hybrid nanosheets are synthesized via a simple solvothermal method for this purpose. The architectures are self-assembled with hybrid nanosheets, which are fabricated through the in situ growth of few-layer MoS2 nanosheets on the surface of graphene substrates. Rooted in the intriguing advantages of sheet-on-sheet structures and 3D features, the composite materials exhibit improved electrochemical lithium storage performances when used as anode materials, in terms of high reversible capacity, superior cycling stability (904mAhg−1 after 200 cycles at 200mAg−1), and high rate capability. It is also employed as integrated electrode for electrochemical water splitting and delivers remarkably enhanced catalytic performance for hydrogen evolution, such as low onset overpotential (110mV), small Tafel slope (47mVdecade−1), and stable cycling performance.