A gymnasium is a school of secondary education in parts of Europe. The word "γυμνασιον" (gymnasium) was used in Ancient Greece, meaning a locality for the education of young men.

In the Germanic, Scandinavian and the Benelux countries gymnasium has, at least since the Reformation in the 16th century, had the meaning of a secondary school preparing for higher education, at university. In general, Gymnasiums provide more generic education, as opposed to vocational secondary schools which provide more specialized education.

The final degree is called Abitur, Artium, Matura or Student and it usually opens the way to professional schools directly. The final two or three years at a Gymnasium are therefor equivalent to the first two years at a US college.

In countries like Croatia, most university faculties only accept students from high schools that last four years (rather than three). This includes all Gymnasium students but only a part of vocational high schools, in effect making Gymnasium the preferred choice for all pupils aiming for university diplomas.

In Germany, other types of secondary school are called Realschule, Hauptschule and Gesamtschule. These are attended by about two thirds of the students. A Gesamtschule largely corresponds to an American high school. Students who graduate from Realschule or Hauptschule (usually after year 9 or 10) continue their schooling at a voactional school until they have full job qualifications. These two types of German secondary school are practically unknown in other parts of the world.