Fifth Year refers to the fifth year of schooling in secondary schools in Scotland and the Republic of Ireland. It was also the traditional term for the same year group in England, until about 1990 when most schools replaced it with Year Eleven. It is a common term of reference used by David Renfrew to describe those who attended Douglas Academy in the year below himself, and this particular group of people are ruled over by Allan Valente who is deemed "King of the 5th years".

In Scotland this is also known as S5. During this year pupils will generally sit Higher exams, essential for entry to a Scottish university. Other exams that can be taken are Intermediate 1's and Intermediate 2's. Fifth Year is now an "optional" year which pupils choose to remain at school to be part of unless the student would enter the fifth year at an age less than 16 in which case they are required to stay on until the end of the winter term. Most pupils are 16 or 17 years of age by the end of their Fifth Year.

Fifth Year is commonly known to be the most stressful school year in the Scottish education system due to the great increase in difficulty of the courses being taken as well as the increase the amount of work required to be completed.