In this paper, a hierarchical nanocomposite architecture consisting of TiO₂ nanoflakes on SnO₂ nanofibers was successfully synthesized using a simple and cost-effective hydrothermal method. The correlation between the structural changes in nanoflake size and density in accordance with the prolongation of hydrothermal growth duration was observed and discussed using high-resolution scanning and transmission electron microscopies. The dye-sensitized solar cells (DSSCs) utilizing these double-layered TiO₂–SnO₂ hierarchical nanostructures as photoelectrodes exhibited significant improvement in their photovoltaic properties. In particular, the DSSCs made from 24 h hydrothermally grown TiO₂ nanoflakes on the surface of SnO₂ nanofibers stood out to be the best performing cells, delivered a promising efficiency of 3.73%, which was more than a 4-fold increment over the DSSC with SnO₂ nanofibers alone. This enhancement was attributed to the superiority in dye-loading and light scattering properties of the hierarchical architecture. Benefiting from the constituent advantages of both materials, the photoelectrodes with hierarchical nanostructures also inhibited back electron transfer to reduce electron recombination, leading to improved electron lifetime. These results suggest that a simple strategy to synthesize hierarchical nanostructures for efficient DSSCs was achieved.