The British National Formulary (BNF) is a United Kingdom (UK) pharmaceutical reference book that contains a wide spectrum of information and advice on prescribing and pharmacology, along with specific facts and details about many medicines available on the UK National Health Service (NHS).

Information within the BNF includes indication(s), contraindications, side effects, doses, legal classification, names and prices of available proprietary and generic formulations, and any other notable points.

It is used by pharmacists and doctors (both general practitioners (GPs) and generalist hospital practitioners, and by other prescribing healthcare professionals (such as nurses, pharmacy technicians, paramedics, and dentists)); as a reference for correct dosage, indication, interactions and side effects of drugs.

It is also used as a reassurance by those administering drugs, for example a nurse on a hospital ward, and even for patients and others seeking an authoritative source of advice on any aspect of pharmacotherapy.

It is published under the authority of a Joint Formulary Committee (JFC),[2] which comprises pharmacy, medical, nursing, and lay representatives; there are also representatives from the Medicines and Healthcare products Regulatory Agency (MHRA), the UK Health Departments, and a national guideline producer.

In addition, the Joint Formulary Committee takes advice on all therapeutic areas from advisers from expert groups; this ensures that the BNF's recommendations are relevant to practice.

In 2023, NICE announced their decision to stop the supply of print BNF to NHS organisations in England.