Objectives: To comprehensively determine the association between oral diseases and high-caffeine beverage intake in adolescents. Methods: Data from 54,653 adolescents who were included in the 20th Korea Youth Risk Behavior Survey (2024) were analyzed. Logistic regression was performed to determine the association between caffeine intake frequency and oral diseases, adjusting for gender, grade, academic achievement, economic status, and toothbrushing frequency. Results: Compared with non-consumers, low-frequency consumers had an increased risk of dental caries (odds ratio [OR]=1.165; 95% confidence interval [CI]: 1.124–1.208), whereas high-frequency consumers had a significantly higher risk (OR=1.186; 95% CI: 1.064–1.320). Similarly, low-frequency consumers had an increased risk of periodontal disease (OR=1.077; 95% CI: 1.033–1.123), whereas high-frequency consumers had a significantly higher risk (OR=1.489; 95% CI: 1.328–1.670). Conclusions: The prevalence of dental caries and periodontal disease increased with higher consumption of high-caffeine beverages. Frequent intake of high-caffeine beverages was significantly associated with oral diseases in Korean adolescents.