Head girl and head boy
|This article does not cite any references or sources. (March 2013)|
United Kingdom and Ireland 
In some British schools, the pupil body (or the headteacher) may elect a head boy and/or a head girl from the pupils. Head boys and head girls are usually responsible for representing the school at events, and therefore must be able to make public speeches. He or she may also be expected to lead fellow prefects in their duties. Deputy head boys and girls may also be appointed, taking on the day-to-day management of the prefects in some institutions, as well as looking after the school and creating a link between teachers and pupils.
Other Commonwealth countries 
Outside of the United Kingdom, many public schools throughout the Commonwealth, particularly in the Caribbean and Asia, use the term head boy or head girl. Many other countries instead elect a president or captain of the student government or senior prefect. However, the title continues to be used for the elected head of the pupillary government at private schools, as well as maintaining currency throughout New Zealand, where almost every secondary school has a head boy and/or girl.
All schools in Hong Kong, India, Pakistan, Sri Lanka, Singapore, UAE and Malaysia, and many in the Commonwealth Caribbean, as well as South Africa, follow the same system as that in the United Kingdom, having a head girl and head boy or head prefect, a vice-head girl/boy, prefects, house captains, monitors and class representatives. The head girl and boy assist the teachers and administration of the school. Ghanaian schools follow a similar system although some schools appoint a head prefect or senior prefect and assistant senior prefect.
In Australia, the system is much the same as that of the United Kingdom. Almost all public secondary schools will have a student council with each year group having elected representatives. There are rarely any vice or deputy roles, with these positions being taken up by the student councillors. The student council is in charge of assisting with the organisation of social events and fund-raising events within the school. In general, it is the main liaising body between the students and staff. The head boy and head girl are generally the "chair" of this council and will represent the school on a government or community level and will represent the students at the school level. They are usually required to present speeches as part of this role, and so should be good at public speaking.
Upper Canada College in Toronto, St. Andrew's College in Aurora, and Ridley College in St. Catharines, Ontario, are all independent schools that use the title head boy differently, applying it to the student who has achieved the highest academic standing in his graduating class; similar, in principle, to the valedictorian at an American high school. What would otherwise be known as head of school at an equivalent British institution is known at Upper Canada College as the head steward.
Outside the Commonwealth 
The term has become familiar to international readers through the Harry Potter books; Hogwarts School is loosely based on British public schools. Schools in other parts of Europe also know this function. In the Netherlands high schools are using the term class representative ("klassenvertegenwoordiger") instead of head girl or -boy.