<p>This study investigates the effects of annealing and of chelating agents, triethanolamine (TEA) and ethylenediaminetetraacetic acid (EDTA), on tin sulfide (SnS) thin films prepared by potentiostatic electrodeposition on ITO-coated glass substrates. The films were annealed at 250 °C for 30 min, under air and under the presence of sulfur. The cyclic voltammetry revealed that the chelating agent’s type impacts the kinetic parameters of the deposition process. It was found that EDTA leads to stable chelates with tin ions compared to the TEA agent. Moreover, chronoamperometry highlighted that TEA enhanced the film’s electrochemical deposition kinetics, resulting in thicker and more compact layers when compared to those achieved with EDTA. XRD analysis showed the successful deposition of orthorhombic SnS films and the improvement of crystallinity by the increase of crystallite size after annealing treatments, especially with sulfurization. Raman spectra confirmed the deposition of pure SnS without annealing, and when annealing, the formation of a small amount of SnS₂ and Sn₂S₃ tin sulfide’s secondary phases. SEM micrographs revealed grain growth and densification. EDX analysis highlighted that both chelating agents and annealing processes affect the elemental composition of the films. Finally, optical studies have demonstrated that annealing increases the band gap energy, and TEA-based films are better for photovoltaic applications.</p>