Graphitic carbon nitride (g-C₃N₄) was hybridized by hierarchical yolk–shell TiO₂ spheres via a solvothermal method by mixing the as-prepared g-C₃N₄ with the precursor of the TiO₂ yolk–shell spheres in dimethylformamide (DMF). The introduction of DMF made the TiO₂ yolk–shell spheres to be dispersed well on the surface of g-C₃N₄, thus improving the specific surface area of the materials. The g-C₃N₄ has a unique two-dimensional layered structure, which is favorable for hybridizing with TiO₂. The sufficient contact interface between TiO₂ and g-C₃N₄ could be beneficial to the separation of photogenerated charges. Multiple reflections of light within the interior cavities of titania microspheres with a yolk–shell structure can increase their light absorption. The photocatalytic experimental results indicated that the as-prepared composite TiO₂/g-C₃N₄ (TCN) showed enhanced photocatalytic activities compared with pure TiO₂ and g-C₃N₄. A suitable combination of g-C₃N₄ with TiO₂ produced the highest photocatalytic activity. Moreover, the photocatalytic activity of TCN with a yolk–shell structure is higher than that of TiO₂/g-C₃N₄ without a yolk–shell structure. Based on our experimental results, a possible photocatalytic mechanism with holes and superoxide radical species as the main active species in photocatalysis was proposed. The TCN photocatalysts prepared in this case, with high photocatalytic activity and high stability, were a promising candidate for possible practical application in industrial production.