Recently, the demand for groundwater has been increasing along with population growth and irrigation practices. Owing to this growth, Egypt's per capita freshwater will severely decrease. The Nubian Sandstone Aquifer System (NSAS) is the great aquifer that extends through several countries and considered the promising potential aquifer in the area. Bahariya Oasis, located in a hypo-arid climate, is mainly dependent on groundwater extracted from the Nubian aquifer, which is considered the source for agricultural and development projects in the oasis. The main aim of the present study is to help the decision-makers in planning the new reclamation land in Bahariya depression. For the study, 52 samples from different aquifers were collected and analyzed to document the processes controlling the chemistry of the groundwater in the (NSAS) and evaluate its quality for irrigation use. Physio-chemical parameters of the collected samples were carried out to estimate the processes that impacted the quality of groundwater. Major ion concentrations of Na+, K+, Mg+2, Ca+2, SO4-2, HCO3-, Cl-, and NO3- were calculated. A combination of irrigation groundwater indexes such as sodium percentage (Na%), chloride content (Cl-), total soluble salts (TDS), and sodium adsorption ratio (SAR) provides guidance to estimate the suitability of irrigation groundwater in Bahariya Oasis. Except in some shallow aquifer locations, the obtained result was referred to as the suitability of groundwater for irrigation.