We demonstrate the successful application of 3D printing (additive manufacturing) to construct high energy density and power density sulfur/carbon cathodes for Li-S batteries. A self-standing 3D-printed sulfur/carbon cathode with high sulfur loading based on a low-cost commercial carbon black was fabricated via a facile robocasting 3D printing process. The 3D-printed sulfur/carbon cathode shows excellent electrochemical performance in terms of capacity, cycling stability, and rate retention by facilitating Li+/e- transport at the macro-, micro-, and nano-scale in Li-S batteries. Meanwhile, the areal loading of the sulfur/carbon cathode can be easily controlled by the number of stacking layers during 3D printing process. The Li-S batteries assembled with the 3D-printed sulfur/carbon cathodes with a sulfur-loading of 3 mg cm−2 deliver a stable capacity of 564 mA h g−1 within 200 cycles at 3 C. Moreover, cathodes with a sulfur-loading of 5.5 mg cm−2 show large initial specific discharge capacities of 1009 mA h g−1 and 912 mA h g−1, and high capacity retentions of 87% and 85% after 200 cycles at rates as high as 1 C and 2 C (equaling to high areal current densities of 9.2 mA cm−2 and 18.4 mA cm−2), respectively.