This study presents a comprehensive analysis of the hydrochemistry of the Tendrara aquifer in the Tendrara region of Morocco. The study encompasses various aspects of the region, including its geography, administration, relief, demography, economy, and climate, to establish a solid understanding of its water facies. Ten water sampling points have been chosen, and standard methods were used to analyze the physicochemical characteristics of the water, temperature, electrical conductivity, and concentrations of different ions and compounds. Descriptive statistics and hydrochemical classifications, including Piper's, Schoeler's, Wilcox's, and ternary classification, were applied to classify and identify different water facies. Additionally, principal component analysis (PCA) was conducted to explore the relationships between different water parameters. The results revealed distinct hydrochemical characteristics within the Tendrara aquifer, with predominantly alkaline water and varying concentrations of potassium, sodium, calcium, magnesium, chlorides, nitrates, bicarbonates, and sulfates. The numerical results indicated that the concentrations of major ions in the Tendrara aquifer varied within the following ranges: potassium (K+) 2.6-47 mg/l, sodium (Na+) 17-170 mg/l, calcium (Ca2+) 40.882-178 mg/l, magnesium (Mg2+) 33.534-159.72 mg/l, chlorides (Cl-) 22.865-244.201 mg/l, nitrates (NO3-) 2.806-237.85 mg/l, bicarbonates (HCO3-) 183-311.1 mg/l, and sulfates (SO42-) 40.392-336.6 mg/l. The electrical conductivity of the water ranged from 660 to 2640 µS/cm, indicating variations in mineral content and overall water quality analysis of the diagram shows that the Tendrara aquifer's subterranean waters are predominantly chloride-rich and sulfate-rich in calcium and magnesium. These findings contribute to a better understanding of the hydrochemistry of the Tendrara aquifer and have implications for water resource management in the region. The knowledge gained from this study can inform decision-making processes related to water treatment, conservation, and protection. It highlights the need for sustainable practices to ensure the availability of clean and safe water for the local population. Further research is recommended to investigate temporal variations, sources of contamination, and the long-term impacts of anthropogenic activities on the Tendrara aquifer's hydrochemistry.