School uniforms are common in primary and secondary schools in many nations. They are the most widely known form of student uniform; other types of which include uniforms worn by students participating in higher vocational training, such as in health occupations.

Traditionally, school uniforms have been subdued and professional. Boys' uniforms often consist of dark trousers and light-colored shirt, tie. Girls' uniforms vary greatly between countries and schooling systems, but typically consist of a dress or a blouse worn either with a skirt, culottes or under a pinafore. Gender-specific uniforms have been a point of contention, with some schools permitting female students to choose either skirts or trousers while still requiring male students to wear trousers. The use of a blazer or suit-like jacket for either gender is also fairly common, especially in cold weather.

In continental Europe, they have not been required in public (state-sponsored) schools. Private schools, though, often have a school uniform or a strict dress code. This is different in the United Kingdom and Ireland, however, where the majority of state secondary schools adopt a uniform for a more formal look.