The Advanced Level General Certificate of Education, commonly referred to as an A-level, is a qualification offered by education institutions in England, Northern Ireland, Wales, Cameroon, and the Cayman Islands. It is also offered in Scotland by a small number of educational institutions, typically private fee-paying schools, where students would normally take the Scottish Qualifications Certificate Higher and Advanced Higher. A-levels are studied over a two-year period and are recognised as the standard for assessing the suitability of applicants for academic courses in English, Welsh, and Northern Irish universities.

Following the introduction of Curriculum 2000 in September 2000 (with the first AS-level examinations held in January 2001 and A2 examinations the following year), an A-level now consists of four (or six for natural sciences) modules studied over two years. Normally, two modules are assessed in the first year, and make up a stand-alone qualification called the "AS-level" (or Advanced Subsidiary level, not to be confused with an older AS-level, the Advanced Supplementary level). Another two modules are assessed at the end of the second year, which make up the "A2". A2 modules do not form a qualification in their own right; the satisfactory completion of the AS and A2 modules in the same subject is required to constitute a complete A-level. Modules are assessed by exam papers marked by national organisations and internally assessed coursework.