In medicine, a surgeon is a person who performs surgery. Surgery is a broad category of invasive medical treatment that involves the cutting of a body, whether human or animal, for a specific reason such to remove a diseased organ or to repair a tear or breakage. Surgeons may be medical doctors, dentists, podiatrists or veterinarians. In earlier times there were also people trained solely in removing bladder stones, but at the present day specialised practitioners would have first been trained in one of the professions already mentioned.

Minimally invasive procedures such as the procedures of interventional radiology are sometimes described as "minimally invasive surgery." The field traditionally described as interventional neuroradiology, for instance, is increasingly called neurointerventional surgery.

Robotic surgery is an area of growing interest.

Surgeon titles

In the United Kingdom, Ireland, Australia and New Zealand most attending or consultant surgeons are distinguished from physicians by being referred to as "Mr," "Mrs", "Ms" or "Miss." This tradition has its origins in the 18th century, when surgeons were barber-surgeons and did not have a degree (or indeed any formal qualification), unlike physicians, who were doctors with a university medical degree.

By the beginning of the 19th century, surgeons had obtained high status, and in 1800, the Royal College of Surgeons (RCS) in London began to offer surgeons a formal status via RCS membership. The title Mister became a badge of honour, and today after someone graduates from medical school with the degrees MBBS or MB ChB, (or variants thereof) in these countries they are called "Doctor" until they are able, after at least four years training, to obtain a surgical qualification: formerly Fellow of the Royal College of Surgeons and now Member of the Royal College of Surgeons or a number of other diplomas, they are given the honour of being allowed to revert back to calling themselves Mr, Miss, Mrs or Ms in the course of their professional practice, but this time the meaning is different. Patients in the UK may assume that the change of title implies Consultant status (and some mistakenly think non-surgical consultants are Mr too), but the length of postgraduate medical training outside North America is such that a Mr (etc) may be years away from obtaining such a post: many doctors used to obtain these qualifications in the Senior House Officer grade, and remain in that grade when they began subspecialty training. By contrast, North American physicians and surgeons are always addressed as "Doctor."

Surgical specialties and allied fields

• Cardiothoracic surgery
• Colon and Rectal surgery
• Dental surgery
• Oral and maxillofacial surgery
• Dermatologic surgery
• Hand surgery
• General surgery
• Breast surgery
• Endocrine surgery
• Hepatopancreatobiliary surgery
• Lower gastrointestinal surgery
• Transplant surgery
• Upper gastrointestinal surgery
• Vascular surgery
• Maxillofacial surgery
• Neurological surgery
• Obstetrics and gynaecology
• Orthopaedic surgery
• Ophthalmology
• Otolaryngology
• Pediatric surgery
• Plastic surgery
• Podiatric surgery
• Surgical oncology
• Trauma surgery
• Urology
• Veterinary surgery