Semiconductor thin films of CuMnS have been deposited onto conductive fluorine-doped tin oxide (FTO) glass substrate using an electrodeposition method to investigate their properties for possible applications. Copper sulfate, manganese sulfate and Thiourea were precursors used for sources of copper, manganese and sulphur ions respectively. The concentration of manganese ions was varied while keeping deposition voltage and time constant at 0.6 and 100 s, respectively. The films were characterized for optical, structural and morphological properties. The results obtained showed that the absorbance of the films is high in the visible (VIS) and near-infrared (NIR) regions but decreases towards NIR. The films transmittance is low in the VIS but increased in the NIR regions. The extinction coefficient is low in the VIS and NIR regions and decreases as concentration of manganese ion increased. The refractive index is high and initially increased slightly from 4.49 to 4.68 in the mid-VIS region while manganese concentration increased from 0.05 to 0.15 M and then decreased to the value of 2.73 as concentration of manganese ion increased further. The optical conductivity is high throughout the VIS and NIR regions while the optical bandgap energy is in the range of 1.5 to 2.05 eV and increases as manganese ion concentration increased. The XRD analysis showed that the deposited thin films of CuMnS are crystalline with average crystallite size and micro-strain in the range of 15.86-24. 45 nm and 3.97× 10–3-6.13× 10–3, respectively. The SEM results showed that the films are composed of particle sizes that are spherical in shape, uniform in sizes and densely packed together and consequently make the film surface rough. These properties exhibited by the films make them good materials for applications in photovoltaic calls, solar control coatings, photothermal applications and many other electronic devices that require high temperatures.