Background To compare the clinical outcomes of two treatment modalities, initial surgery and primary definitive radiotherapy (RT), in Taiwanese patients diagnosed with cT1−2N0M0 oral cavity squamous cell carcinoma (OCSCC). Methods Between 2011 and 2019, we analyzed data for 13,542 cT1−2N0M0 patients who underwent initial surgery (n = 13,542) or definitive RT with a dosage of at least 6600 cGy (n = 145) for the treatment of OCSCC. To account for baseline differences, we employed propensity score (PS) matching, resulting in two well‐balanced study groups (initial surgery, n = 580; definitive RT, n = 145). Results Before PS matching, the 5‐year disease‐specific survival (DSS) rates were 88% for the surgery group and 58% for the RT group. After PS matching, the 5‐year DSS rates of the two groups were 86% and 58%, respectively. Similarly, the 5‐year overall survival (OS) rates before PS matching were 80% for the surgery group and 36% for the RT group, whereas after PS matching, they were 73% and 36%, respectively. All these differences were statistically significant (p < 0.0001). A multivariable analysis identified treatment with RT, older age, stage II tumors, and a higher burden of comorbidities as independent risk factors for both DSS and OS. We also examined the 5‐year outcomes for various subgroups (margin ≥5 mm, margin <5 mm, positive margins, RT combined with chemotherapy, and RT alone) as follows: DSS, 89%/88%/79%/63%/51%, respectively, p < 0.0001; OS, 82%/79%/68%/39%/32%, respectively, p < 0.0001. Conclusions In Taiwanese patients with cT1−2N0M0 OCSCC, a remarkably low proportion (1.1%) completed definitive RT. A significant survival disparity of 30% was observed between patients who underwent initial surgery and those who received definitive RT. Interestingly, even patients from the surgical group with positive surgical margins exhibited a significantly superior survival compared to those in the definitive RT group. Patients with cT1−2N0M0 oral cavity cancer who underwent initial surgery demonstrated significantly improved disease‐specific and overall survival rates compared to those who received primary definitive radiotherapy (≥6600 cGy), even after propensity score matching. Subgroup analyses further revealed that survival outcomes remained significantly better for the positive margin subgroup compared to the radiotherapy group, irrespective of whether they received concurrent chemotherapy.