Osteopathic medicine is a branch of medicine based on the premise that the primary role of the physician is to facilitate the body's inherent ability to heal itself. Though practiced mainly in the United States, osteopathic medicine shares a common historical origin with a type of complementary medicine practiced worldwide, known as osteopathy. Physicians who graduate from osteopathic medical schools are sometimes known as osteopathic physicians and hold a doctorate in osteopathic medicine (D.O.), while holders of a similar, but far more common M.D. degree are known as allopathic physicians. The existence of this distinction and of D.O.s as licensed physicians is not widely known.

Founded as osteopathy by frontier physician Andrew Taylor Still as a radical rejection of the prevailing system of medical thought of the 19th century, the profession gradually moved closer to mainstream medicine in its practices, and came to be called "osteopathic medicine" within the United States. Today, the training of osteopathic physicians is virtually identical to that of M.D. physicians. Dennis L. Kasper, Eugene Braunwald, Anthony S. Fauci, Stephen L. Hauser, Dan L. Longo, J. Larry Jameson, and Kurt J. Isselbacher, Eds. Chapter 10. Complementary and Alternative Medicine Harrison's Principles of Internal Medicine, 16th Ed. 2005. McGraw Hill. Osteopathic physicians use all conventional methods of diagnosis and treatment but are trained to place additional emphasis on the achievement of normal body mechanics as central to maintaining good health. D.O. physicians receive training in Osteopathic Manipulative Medicine (OMM), a form of manual therapy shown to be of some benefit for patients with certain musculo-skeletal disorders. However, this form of therapy is used by a minority of osteopathic physicians in actual practice. In the United States, osteopathic medicine is considered by some both a profession and a social movement. Zuger A. Scorned No More, Osteopathy Is on the Rise. New York Times. 17 Feb 1998.

Although U. S. osteopathic medical physicians currently may obtain licensure in 47 countries, osteopathic curricula in countries other than the United States differs. D.O.s outside the U. S. are known as "osteopaths" and their scope of practice excludes allopathic medical therapies and relies more exclusively on osteopathic manipulative medicine and other alternative medical modalities.

Discussions about the future of osteopathic medicine frequently debate the feasibility of maintaining distinctiveness within the broader U.S. physician community. More recently, the topic of for-profit medical education has become an issue.