Patients with celiac disease have an increased rate of malignancies that are not limited to lymphomas. Thyroid carcinoma has not previously been associated with celiac disease. However, among a cohort of patients with celiac disease, we identified an increased risk of papillary carcinoma of the thyroid, standard morbidity ratio of 22.52 (95% confidence interval 14.90-34.04; P < .001), compared to United States national surveillance data. These patients were on a gluten-free diet. Only 1 had Hashimoto's thyroiditis, suggesting that mechanisms apart from autoimmune thyroiditis contribute to the increased risk of carcinoma of the thyroid in celiac disease.