Over the last decade, lithium–sulfur (Li–S) batteries have been extensively studied because of the abundance of sulfur, their environmental benignity, and high gravimetric (2600 W h kg−1) and volumetric (2800 W h L−1) energy densities. However, their unique electrochemical behavior involving the formation of dissolved polysulfide intermediate species and the insulating nature of sulfur and Li2S are the main drawbacks that must still be overcome. To tackle these limitations, solutions such as appropriate cathode architecture design, electrolyte optimization, and lithium metal stabilization have been proposed. Recently, high areal sulfur loading, a high sulfur content, and a high electrolyte-to-sulfur ratio have also become prominent issues for the commercialization of the Li–S batteries. This paper reviews a wide range of reports on the design of structural and functional nanomaterials for Li–S batteries and suggests future research directions.