<p>Twenty tap water samples collected from various locations across the Ranya region, Iraqi Kurdistan Region, were examined to assess radon concentrations alongside key physicochemical parameters using a Rad7 radon detector. The measured radon concentrations ranged from 0.45 to 3.85 Bq L⁻¹, with a mean of 1.40 Bq L⁻¹, all of which fell well within the permissible limits established by the WHO and USEPA. Annual ingestion dose and annual inhalation dose were estimated for three age groups, adults, children, and infants. All calculated dose rate values remained below the WHO reference level of 100 µSv y⁻¹. Among the age groups, infants recorded the highest annual ingestion dose and annual inhalation dose values compared to adults and children. The ingestion pathway contributed a greater dose than the inhalation pathway across all age groups. Statistical analysis confirmed a significant correlation between radon concentration and the estimated radiological dose, whereas no significant relationship was observed between radon concentration and the majority of physicochemical parameters measured in the tap water samples. These findings establish a baseline radiological dataset for the Ranya region and demonstrate that continued monitoring of tap water supplies across different distribution networks and geological zones is essential for ensuring safe drinking water quality and sustainable public health management.</p>