Connective tissue disorders in diabetes encompass the major long‐term complications, which can be attributed to alternation in the quantity and quality of structural macromolecules of the extracellular matrix. This chapter reviews the abnormalities of interstitial connective tissue involving skeleton, joints, skin, and periarticular tissues that have been considered to be associated with diabetes, including osteopenia in children and adults; hyperostosis; osteoarthritis; rheumatoid arthritis; osteolysis; scleroderma diabeticorum; Dupuytren disease; stiff hand syndrome of Lundbaek; carpal tunnel syndrome; flexor tenosynovitis; adhesive capsulitis of the shoulder and shoulder–hand syndrome; and limited joint mobility (LJM). Despite an extensive literature defining the characteristic features of the six distinct conditions resulting in limitation of hand joint mobility, recognition of the fact that these are different entities, although they may coexist, is often not appreciated. Among these conditions affecting hand joint mobility, LJM is unique in that it can occur in children and adolescents, in whom it was originally described, does not occur in the nondiabetic young population, is an important risk marker for other complications, correlates with long‐term metabolic control, and has markedly decreased in frequency over the past 20 years, presumably as a result of improved control of type 1 diabetes in children.