Noble metal-free counter electrodes using a co-catalytic loading of MoS₂ nanosheets onto Cu₂ZnSnS₄ microspheres are investigated by means of CuInS₂–CdSe quantum dot (QD) co-sensitized solar cells fabricated with single crystalline ZnO nanowires. An ex situ electrophoretic deposition route is employed to deposit QDs onto ZnO nanowires that are epitaxially grown on ZnO seed layered FTO substrates. Hydrothermally grown ZnO nanowires have also established an excellent stability against the bias conditions applied to fabricate the photoanodes of the devices. The superior photovoltaic performance of CuInS₂–CdSe QD co-sensitized cells is compared with that of bare CuInS₂ and CdSe counterparts, using current–voltage and incident photon-to-current conversion efficiency measurements. The present study also demonstrates an enhanced performance of the devices fabricated with 1.0 wt% of MoS₂ loaded Cu₂ZnSnS₄ based counter electrodes in contrast to bare Cu₂ZnSnS₄. Hydrothermal loading of MoS₂ onto Cu₂ZnSnS₄ generates an electrically interconnected network of Cu₂ZnSnS₄ microspheres, leading to facile charge transport in the counter electrode of the devices. MoS₂ in its nanosheet form acts as an electrical bridge that interlinks the Cu₂ZnSnS₄ microspheres. Additionally, a favorable band energy alignment of Cu₂ZnSnS₄ and MoS₂ stimulates the charge transfer dynamics in the Cu₂ZnSnS₄–MoS₂ composite. Electron transport and recombination kinetics of the devices are measured using electrochemical impedance spectroscopy.