The construction of advanced cathode materials is indispensable and vital for developing high-performance lithium–sulfur batteries. Herein, we develop a facile in-situ route to synthesize three-dimensional reduced graphene oxide supported Li2S/carbon composite (3D-rGO-Li2S/C). The Li2S/C nanoparticles are intimately anchored on the surface of 3D-rGO forming an integrated 3D porous composite. Due to the improved conductivity and reduced polysulfide dissolution, the 3D-rGO-Li2S/C cathode exhibits enhanced electrochemical performances with a high initial capacity of 819 mAh g−1 at 0.1C, as well as good cycling stability with a capacity retention of 415 mAh g−1 after 100 cycles at 1C. The integrated 3D conductive network is responsible for the enhancement of the electrochemical properties by providing fast ion/electron transfer and high mechanical stability.