Ethio-leather industry (ELICo) is one of the most important factories in Ethiopia, located in Addis Ababaâ€™s Akaki Kality sub-city, with an annual capacity of 6600 tons. The company generates a maximum of 1200 m3/day of wastewater effluent. Company uses raw water at a rate of 2000 m3/day on average, equivalent to 90 m3 of water per ton of finished leather goods. This research investigated the efficiency of the tannery wastewater treatment plant for water recycles as a substitute for groundwater. It has also evaluated the performance of the wastewater treatment plant using Hydromantis GPS-X, a commercially available wastewater treatment plant modeling and simulation software tool. For this task Physicochemical laboratory analysis, field measurement and secondary data, were used to acquire the input data for process modeling and simulation. It tested all parameters using the Water and Wastewater Standard Method from the Physico-chemical analysis of the wastewater generated from the plant. This paper understands, effluent water quality found below the standard discharge limit by Ethiopian Environment, Forest and Climate change Commission. According to physico chemical characteristics treatment plant has 93.6% of COD, 97.44% of BOD5 and TSS of 98.8% removal efficiency this is some of conducted parameters. In this research, the GPS-X model was run after a sensitivity analysis calibration and validation phase. According to the result of the steady-state and time dynamic sensitivity analysis, the model was sensitive to changes in input and good enough to be used as a parameter prediction. This research successfully validated the developed model while meeting the assumption of the modelsâ€™ constant stoichiometry and kinetic coefficients for any plant influent characteristics. Model validation also shows that it is 76.11 percent accuracy in predicting plant performance and the simulation result shows a satisfactory effluent water quality parameter. Therefore, this research discovered that it can be recycle in some parts of the tannery process. The findings of the physicochemical characterization and process simulation evaluation substantiated this.