Graphene/titania (G/TiO2) nanocomposite photoanodes were fabricated for CdS quantum dots sensitized solar cells (QDSSCs) applications. The effect of G/TiO2 ratio (0, 0.1, 0.2, 0.5, and 1.0 wt.%) on the photovoltaic performance of CdS QDSSCs was investigated. CdS QDs were deposited onto G/TiO2 nanocomposite films by successive ionic layer adsorption and reaction (SILAR) technique for six cycles. The current density–voltage (J–V) characteristic curves of the assembled solar cells were measured at AM1.5 simulated sunlight. The optimal G/TiO2 ratio was 0.2 wt.% for photovoltaic performance. CdS QDSSCs based on 0.2 wt.% G/TiO2 nanocomposite photoanode achieve 32% increase in conversion efficiency (g) compared with those based on plain TiO2 NPs photoanode. The photovoltage–decay curves of the assembled cell were recorded. The electron–hole back recombination rates decrease significantly for CdS QDSSCs based on 0.2 wt.% ratio of G/TiO2 nanocomposite photoanode. The lifetime constants (s) is much larger for CdS QDSSCs based on 0.2 wt.% ratio of G/TiO2 nanocomposite photoanode compared to those based on plain TiO2 NPs photoanodes.