This research focused on assessing groundwater quality in the Alton Kopri, Kirkuk Province, northern Iraq. Twenty-two samples were selected from twenty-two wells randomly distributed in the study area to assess the subsurface water for drinking purposes. The samples were analyzed for parameters (pH, T.D.S, Na+, Mg2+, K+, Ca2+, NO3-, SO42-, HCO3-, and Cl-) to compute Water Quality Index (WQI). Pearson's correlation and principal components analysis (PCA) were adopted to study the physicochemical parameters sources in groundwater. The dominant cations were ordered as follows: Na > Ca > Mg > K, and the dominant anions were arranged as follows: SO3 > Cl > HCO3 > NO3. The average concentrations of TDS, Ca, Mg, Na, SO4, and Cl were 1118.45, 173.54, 132.59, 341.36, 873.63, and 414.50, respectively, surpassing the maximum permissible limits set by WHO. The average concentrations of K, NO3, HCO3, and pH were 5.90, 35.02, 172, and, 8.05 respectively, and were within acceptable limits. The WQI ranged from 33.3 to 1024. The findings designated that 23% of the samples were categorized as excellent, 27% as good, 18% as poor, 14% as very poor, and 18% as inappropriate for drinking purposes. The Pearson correlation matrix has been created and analyzed to appraise the important factors impacting groundwater quality. The PCA technique was adopted to analyze water quality parameters, resulting in the extraction of three components that together account for 81.574% of the total variance. The extracted components suggest that the predominant contributors to groundwater contamination include geological characteristics, agricultural practices, precipitation, domestic wastewater, and manufacturing activities. This study stands out from others due to various local factors that impact groundwater quality in the Alton Kopri area. Agricultural practices, including fertilizer and pesticide use, lead to chemical seepage into the aquifer, while pastoral activities contribute organic contaminants. Insufficient sewage infrastructure in some areas results in wastewater infiltration. The region’s geology, dominated by limestone and clay, affects groundwater hardness and heavy metal levels. Additionally, the Little Zab River, which recharges groundwater, can transport pollutants during floods. Minor industrial activities may also introduce trace metals and oils. Understanding these influences is key to interpreting water quality variations and informing sustainable management strategies.