Diabetology is the clinical science of diabetes mellitus, its diagnosis, treatment and follow-up. It can be considered a specialised field of endocrinology.

The term diabetologist is used in several ways. In North America over the last 40 years it is most often used for an internist who through practice and interest develops expertise in diabetes care without having formal training or board certification in endocrinology. Diabetology is not a recognized medical specialty and has no formal training programs leading to board certification. In other contexts the term diabetologist refers to any physician, including endocrinologists, whose practice and/or research efforts are concentrated mainly in diabetes care.

Apart from regulating medication (e.g. insulin) dosage and timing, a diabetologist will also concern himself with the potential consequences of diabetes, e.g. retinopathy, nephropathy and peripheral neuropathy.