The National Institute for Health and Care Excellence (NICE) is an executive non-departmental public body of the Department of Health and Social Care in England that publishes guidelines in four areas:

• the use of health technologies within England's National Health Service (NHS) and NHS Wales (such as the use of new and existing medicines, treatments and procedures)
• clinical practice (guidance on the appropriate treatment and care of people with specific diseases and conditions)
• guidance for public sector workers on health promotion and ill-health avoidance
• guidance for social care services and users.

These appraisals are based primarily on evidence-based evaluations of efficacy, safety and cost-effectiveness in various circumstances.

It serves both the English NHS and the Welsh NHS. It was set up as the National Institute for Clinical Excellence in 1999, and on 1 April 2005 joined with the Health Development Agency to become the new National Institute for Health and Clinical Excellence (still abbreviated as NICE). Following the Health and Social Care Act 2012, NICE was renamed the National Institute for Health and Care Excellence on 1 April 2013 reflecting its new responsibilities for social care, and changed from a special health authority to an executive non-departmental public body (NDPB).

NICE was established in an attempt to end the so-called postcode lottery of healthcare in England and Wales, where availability of treatments depended on the NHS Health Authority area in which the patient happened to live, but it has since acquired a high reputation internationally as a role model for the development of clinical guidelines. One aspect of this is the explicit determination of cost–benefit boundaries for certain technologies that it assesses. NICE also plays an important role in pioneering technology assessment in other healthcare systems through NICE International, established in May 2008 to help cultivate links with foreign governments. NICE International has received financial support from the Bill & Melinda Gates Foundation and Rockefeller Foundation.