国民保健署（英语：National Health Service，简称NHS），是对英国以下四大公型医疗系统的统称：

国民保健署的经费主要来自全国中央税收，用以向公众提供一系列的医疗保健服务，合法居于英国的人士可以免费享用当中大部份的服务。国民保健署旗下四大系统各自独立运作，并拥有各自的管理层、规例和法定权力，互不从属。

虽然只有英格兰地区的公营医疗系统是正式称为「国民保健署」，但全国四大公营医疗系统都被普遍称为「NHS」。国民保健署最初经过1946年、1947年和1948年的多项立法工作，最终由当时的工党政府在1948年设立。NHS威尔斯原本属于英格兰国民保健署的一部份，但管理权到1969年分拆到威尔斯大臣手上，1999年再进一步下放到威尔斯政府。

Each of the four countries of the United Kingdom has a publicly funded health care system referred to as the National Health Service (NHS). The terms "National Health Service" or "NHS" are also used to refer to the four systems collectively. All of the services were founded in 1948, based on legislation passed in 1946, 1947 and 1948, by the Labour Government that had been elected in 1945 with a manifesto commitment to implement the Beveridge Report recommendation to create "comprehensive health and rehabilitation services for prevention and cure of disease". NHS Wales was originally part of the same structure as England until powers over the NHS in Wales were firstly transferred to the Secretary of State for Wales in 1969 and thereafter, in 1999, to the Welsh Assembly (now the Welsh Government) as part of Welsh devolution.