A sulfur/graphene composite is prepared by loading elemental sulfur into three-dimensional graphene (3D graphene), which is assembled using a metal ions assisted hydrothermal method. When used as cathode materials for lithium–sulfur (Li–S) batteries, the sulfur/graphene composite (S@3D-graphene) with 73 wt % sulfur shows a significantly enhanced cycling performance (>700 mAh g−1 after 100 cycles at 0.1C rate with a Coulombic efficiency > 96%) as well as high rate capability with a capacity up to 500 mAh g−1 at 2C rate (3.35 A g−1). The superior electrochemical performance could be attributed to the highly porous structure of three-dimensional graphene that not only enables stable and continue pathway for rapid electron and ion transportation, but also restrain soluble polysulfides and suppress the “shuttle effect”. Moreover, the robust structure of 3D graphene can keep cathode integrity and accommodate the volume change during high-rate charge/discharge processes, making it a promising candidate as cathode for high performance Li–S batteries. Display omitted •Three-dimensional graphene is assembled by a simple hydrothermal reduction.•The 3D graphene shows a hierarchical porous morphology and robust structure.•Sulfur content up to 73% is loaded in 3D graphene.•The composite shows high specific capacity and stable capacity retention.•The unique 3D structure enables high-rate capability.