Background: Periodontitis and coronavirus disease (COVID-19) both exhibit an exaggerated inflammatory response as common traits. Given that periodontal diseases have been linked to respiratory illnesses like pneumonia, it is quite possible that periodontitis and COVID-19 are related. Therefore, the purpose of the current study was to ascertain whether the severity of COVID-19 and periodontal disease are related. Methods: A retrospective study was done using the 3 years of patients' medical and dental records in the University Hospital. A telephone interview was employed to estimate the severity of symptoms got through COVID-19 infection. The data obtained were subjected to statistical analysis. The Chi-square test, with statistical significance set at 0.05, was used to determine the relationship between the severity of periodontal disease and the severity of COVID-19. Results: It was seen that there was a strong relationship between the severities of COVID-19 disease and periodontal disease. The mildest gingivitis cases (63%), Stage 1 periodontitis (62.9%), were associated with the COVID-19-negative group, whereas the most severe gingivitis cases (85.7%), Stage 4 periodontitis group (66.66%), were associated with COVID-19-positive group. In comparison to those without periodontitis, patients with periodontitis had a 1.54 times higher risk of COVID-19 complications (P = 0.048). Patients who had comorbidities were 2.49 times to have COVID-19 complications (P = 0.02). Conclusion: The observations presented above lead to the conclusion that COVID-19 and periodontal disease severities are related. Understanding the potential association between periodontitis and COVID-19 through systemic inflammation could be a means of achieving a high-quality medical care. To validate the findings, additional research with larger samples is required.