Introduction <p>Histopathologic examination of biopsy specimen is the gold standard for diagnosis of oral malignancy. Non-invasive approaches, such as saliva-based biomarker assays, offer promise for screening and rapid on-site evaluation. Cancer Antigen 125 (CA125), a high molecular weight glycoprotein and transmembrane mucin, has demonstrated elevated levels in epithelial malignancies and is detectable in saliva.</p> Aim <p>This study aims to evaluate the median salivary CA125 levels between healthy cohorts, patients with Oral Potentially Malignant Disorders (OPMDs) and patients with Oral Squamous Cell Carcinoma (OSCC).</p> Materials and methods <p>The cohort of subjects included comprised three groups: Group I (healthy controls), Group II (patients with OPMDs), and Group III (patients with OSCC). Unstimulated whole saliva was collected from all participants by passive drooling and analysed using CA125 Enzyme-linked immunosorbent assay (ELISA).</p> Results <p>81 participants were included, healthy (<i>n</i> = 28), OPMD (<i>n</i> = 27), and OSCC (<i>n</i> = 26). There was no discrepancy between clinical and histopathological diagnoses of any patient. Median (IQR) salivary CA125 levels were 5.75 U/mL (2.90-10.26) in Control Group I, 14.11 U/mL (10.75–28.94) in OPMD Group II, and 72.81 U/mL (19.47-120.81) in OSCC Group III, which was statistically highly significant (<i>p</i> &lt; 0.001). Further, CA125 levels correlated moderately with OSCC stages (Spearman’s rho = 0.524, <i>p</i> = 0.006).</p> Conclusion <p>Salivary CA125 demonstrated potential as a non-invasive biomarker for OPMD &amp; OSCC screening and detection but requires further validation.</p>