© 2021 John Wiley & Sons LtdBackground: There are scarce published data in differentiated thyroid cancer patients about new coronavirus disease 2019 (COVID-19) disease outcomes and mortality. Here, we evaluated COVID-19 infection outcomes and mortality in thyroid cancer patients with COVID-19 infection. Design and methods: We included a cohort of patients with thyroid cancer with PCR-confirmed COVID-19 disease from 11 March to 30 May 2020 from the Turkish Ministry of Health database in our nationwide, retrospective study. We compared the mortality and morbidity of COVID patients with or without thyroid cancer. Univariate and multivariate analyses were used to assess the independent factors for mortality, length of hospital stay and intensive care unit (ICU) admission and mechanical ventilation. We also analysed the effect of radioiodine treatment on severity and death rate of COVID-19 disease. Results: We evaluated 388 COVID-19 patients with thyroid cancer [median age: 54 years, interquartile range (IQR) 18 years, males: 23%] and age and gender-matched 388 COVID-19 patients without thyroid cancer. Patients with thyroid cancer had a similar mortality ratio compared with the non-cancer group. Among patients with thyroid cancer, age, presence of diabetes mellitus, asthma/COPD, heart failure, chronic kidney disease, prior coronary artery disease, RAS blocker usage and low lymphocyte count were associated with mortality. Radioactive iodine (RAI) treatment and cumulative radioactive iodine dosage did not negatively affect the severity and mortality of COVID-19 disease in our patient group. Conclusions: Our study indicated that history of thyroid cancer did not have an increased risk of mortality or morbidity in COVID-19 disease. Besides, RAI therapy history and doses of radioactive iodine did not affect mortality or outcome.