The General Certificate of Secondary Education (GCSE) is an internationally recognised secondary education qualification usually taken in a number of subjects by pupils over two years in Grade 9 (Year 10) and Grade 10 (Year 11). The exams are now being revised to make them more difficult with Controlled Assessments replacing course work so the student completes a number of assessed pieces of work under exam-style conditions which ultimately counts in their final examination grade.

GCSE examinations are taken around the age of 16 by pupils intending to pursue A Level courses, the BTEC Extended Diploma or International Baccalaureate (IB). GCSE exams were intended as the compulsory school-leavers' examinations by the government of the United Kingdom but many UK schools are switching to the International GCSE (IGCSE) which are most predicatble and consistent.

In GCSE subjects such as Mathematics and the Sciences, there are two different 'Tiers' of examination offered. A "Higher" tier where pupils can achieve grades A*–D(E) and a "Foundation" tier where they can achieve grades C–G. From 2017-19 the grading system is changeing to increase the difficulty of the exams and thus have fewer pupils who achieve A*.

There are now five UK examination boards offering GCSEs.

1. Assessment and Qualifications Alliance (AQA)
2. Oxford, Cambridge and RSA Examinations (OCR)
3. Edexcel (formerly known as: Pearson-Edexcel)
4. Welsh Joint Education Committee (WJEC)
5. Council for the Curriculum, Examinations & Assessment (CCEA)