Fibromyalgia and chronic widespread pain syndromes are among the commonest diseases seen in rheumatology practice. Despite advances in the management of these conditions, they remain significant causes of morbidity and disability. Autoimmune thyroid disease is the most prevalent autoimmune disorder, affecting about 10 % of the population, and is a recognized cause of fibromyalgia and chronic widespread pain. Recent reports are shedding light on the mechanisms of pain generation in autoimmune thyroid disease-associated pain syndromes including the role of inflammatory mediators, small-fiber polyneuropathy, and central sensitization. The gradual elucidation of these pain pathways is allowing the rational use of pharmacotherapy in the management of chronic widespread pain in autoimmune thyroid disease. This review looks at the current understanding of the prevalence of pain syndromes in autoimmune thyroid disease, their likely causes, present appreciation of the pathogenesis of chronic widespread pain, and how our knowledge can be used to find lasting and effective treatments for the pain syndromes associated with autoimmune thyroid disease.