Synthesis and characterization of Mn-doped Sb2S3 thin films (TFs) prepared by chemical bath deposition (CBD) at room temperature have been documented and their structural, optical, morphological, magnetic and photovoltaic properties have been examined for the first time. Their structural properties reveal that the Mn-doped Sb2S3 TF has an orthorhombic phase structure of Sb2S3, and that the grain size of the Mn-doped Sb2S3 TF (72.9 nm) becomes larger than that of undoped Sb2S3 TF (69.3 nm). It has been observed that Mn content causes the Sb2S3 TF band gap to decrease. This situation clearly correlates with band tailing due to the impurities that are involved. The morphological properties have revealed that the shape of the Mn-doped Sb2S3 TF is more uniform than the shape of its undoped counterpart. The study on its magnetic properties has demonstrated that the Mn-doped Sb2S3 TF exhibits paramagnetic behavior. Its paramagnetic Curie-Weiss temperature was found to be -4.1 K. This result suggests that there is an anti-ferromagnetic interaction between Mn moments in the Mn-doped Sb2S3 TF. Incident photon to electron conversion efficiency (IPCE) and J-V measurements were also carried out for the Mn-doped Sb2S3 TF for the first time. The results have indicated that the Mn-doped Sb2S3 TF can be utilized as a sensitizer to improve the performance of solar cells. Another important observation on the photovoltaic properties of Mn-doped Sb2S3 TF is that the spectral response range is wider than that of undoped Sb2S3 TF. Our study suggests that the introduction of dopant could serve as an effective means of improving the device performance of solar cells.