In the medical profession, a general practitioner (GP) or family physician is a physician who treats acute and chronic illnesses and provides preventive care and health education to patients of all ages. GPs' duties are not confined to specific fields of medicine, and they have particular skills in treating people with multiple health issues. They are trained to treat patients to levels of complexity that vary between countries. The term "primary care physician" is more usually used in the US. In Asian countries like India, this term has been replaced mainly by Medical Officers, Registered Medical Practicioner etc.

A core element in general practice is continuity that bridges episodes of various illnesses. Greater continuity with a general practitioner has been shown to reduce the need for out-of-hours services and acute hospital admittance. Continuous care by the same general practitioner has been found to reduce mortality.

The role of a GP can vary greatly between (or even within) countries. In urban areas of developed countries, their roles tend to be narrower and focused on the care of chronic health problems; the treatment of acute non-life-threatening diseases; the early detection and referral to specialised care of patients with serious diseases; and preventive care including health education and immunisation. Meanwhile, in rural areas of developed countries or in developing countries, a GP may be routinely involved in pre-hospital emergency care, the delivery of babies, community hospital care and performing low-complexity surgical procedures. In some healthcare systems GPs work in primary care centers where they play a central role in the healthcare team, while in other cases GPs work as sole practitioners.

The term general practitioner or GP is common in the United Kingdom, Republic of Ireland, Australia, Canada, Singapore, South Africa, New Zealand and many other Commonwealth countries. In these countries, the word "physician" is largely reserved for certain other types of medical specialists, notably in internal medicine. While in these countries, the term GP has a clearly defined meaning, in North America the term has become somewhat ambiguous, and is sometimes synonymous with the terms family doctor or primary care physician, as described below.

Historically, the role of a GP was once performed by any doctor with qualifications from a medical school working in the community. However, since the 1950s, general practice has become a specialty in its own right, with each country having specific training requirements. The 1978 Alma Ata Declaration set the intellectual foundation of primary care and general practice.