We developed an RP-HPLC-based quantitative analytical method applicable to dissolution testing for continuous quality control of oral semaglutide tablets and verified it through method validation. The aim of this study was to demonstrate that the developed method can reliably evaluate the dissolution behavior of semaglutide tablets. Analysis was performed using RP-HPLC with a C18 column (5 µm, 4.6 × 150 mm), and the conditions for mobile phase composition, flow rate, injection volume, detection wavelength, and column temperature were optimized. In the system suitability test, the RSD (%) was 0.13%, which met the acceptance criteria, and specificity was ensured with no interference between the active ingredient and excipients. The calibration curve showed linearity within the concentration range of 20–120% of the test solution with a correlation coefficient (r²) greater than 0.999. The results of accuracy, precision, and robustness all satisfied the acceptance criteria, with no inter-analyst variability or matrix effects observed. Finally, the limit of detection (LoD) and limit of quantitation (LoQ) were confirmed, verifying the validity of the method. The dissolution method established in this study provides a reliable tool for the formulation development and quality control of oral semaglutide tablets and is expected to contribute to improving analytical efficiency for peptide-based formulations in the future.