This study aims to investigate the influence of SILAR cycle on the energy bandgap of Iron Copper Sulphide (FeCuS) thin films deposited on soda-lime glass substrate (SLG). A Successive Ionic Layer Adsorption and Reaction (SILAR) method is one of the chemical methods for making uniform and large area thin films, which is based on immersion of substrates into separately placed cationic and anionic precursors. The technological importance of chemically deposited iron copper sulphide (FeCuS) using SILAR technique vis-à-vis the effect of SILAR cycle on the energy band gap of the deposited thin films has not been unraveled. Thin films of Iron Copper Sulphide were grown on soda-lime glass substrate (SLG) by a simple solution based Successive Ionic Layer Adsorption and Reaction (SILAR) technique at room temperature (300 K) with EDTA, TEA and NH4OH as complexing agents at different SILAR cycles (20, 30 and 40 cycles) of deposition. The thin films grown were characterized using Avantes UV-VIS spectrophotometer (Avalight-DH-S-BAL) in the wavelength range 200-1000nm and Four Point Probe machine (Keithley 4ZA4 2400 Sourcemeter, manufactured by Tektronix Company). The optical properties considered revealed high absorbance and reflectance but low transmittance in the UV region; low values of absorbance and reflectance accompanied with high transmittance in the VIS region. Moreover, the resistivity of the grown thin film varied from 9.480 x 106 Ωm to 4.366 x 107 Ωm in order of increasing SILAR cycle, direct band gap of 3.76 e V, 3.51 e V and 3.42 e V were obtained. These properties suggest that the films are suitable for solar cell and optoelectronic applications.