Antimony selenide thin films have been prepared onto tin oxide coated glass substrates by potentiostatic electrodeposition from an aqueous acid bath containing K(SbO)C4H4O6⋅0.5H2O and H2SeO3 at 25°C. The electrodeposition mechanism was investigated by cyclic voltammetry. The compositional, morphological, structural, optical, and electrical properties of the deposited films have been studied using energy-dispersive X-ray spectroscopy (EDS), environmental scanning electron microscopy (ESEM), Raman spectroscopy (RS), UV–VIS spectra, and photoelectrochemical tests (PEC), respectively. The formation of antimony selenide was confirmed to proceed via an induced codeposition mechanism: Se deposition occurs first, inducing the deposition of Sb, then, the deposited Sb would further promote the deposition of Se. The influence of deposition potential on the composition, morphology, and structure of the antimony selenide thin films was also explored. Sb2Se3 thin films with homogeneous morphology and near stoichiometric composition can be obtained, and exhibit good optical properties with absorption coefficient of higher than 105 cm−1 and band gap of 1.07±0.01eV, as well as electrical properties with p-type conductivity and excellent photoelectrochemical activity.