CXCL10 (rs201830102) is a chemokine involved in immune cell recruitment, while its receptor, CXCR3 (rs779120264), mediates immune responses through the activation of T cells. These genes are critical in the immune response to viral infections, including COVID-19. The study aimed to explore the relationship between polymorphisms in the CXCL10 gene and CXCR3 receptor with disease severity in COVID-19 patients. In this cross-sectional analytical study, 100 COVID-19 patients were enrolled after ethical approval, and written informed consent was obtained from each participant. Polymorphisms in CXCL10 and CXCR3 were analyzed by sequencing, while biochemical and hematological parameters were assessed using appropriate methods. Descriptive and inferential statistics were employed to analyze continuous and categorical data. Significant associations were observed between severe COVID-19 cases and elevated levels of serum D-dimer, ferritin, random blood sugar (RBS), neutrophils, and erythrocyte sedimentation rate (ESR), along with reduced hemoglobin levels. Lymphocyte and platelet counts were significantly lower with increased disease severity. The wild genotype of CXCL10 was notably associated with elevated ferritin levels, suggesting that certain gene variants may offer protective effects. However, no significant correlation was found between CXCR3 and CXCL10 polymorphisms and other serum biomarkers. Our study confirmed a significant rise in serum D-dimer, ferritin, RBS, neutrophils, and ESR, along with a reduction in hemoglobin, lymphocyte, and platelet counts in severe COVID-19 cases compared to mild ones. Notably, mutations in the CXCL10 gene were linked to less severe COVID-19 outcomes.