Numerus clausus ("closed number" in Latin) is one of many methods used to limit the number of students who may study at a university. In many cases, the goal of the numerus clausus is simply to limit the number of students to the maximum feasible in some particularly sought-after areas of studies.

However, in some cases, numerus clausus policies were in effect religious or racial quotas, both in form and motivation.

The numerus clausus is currently used in countries and universities where the number of applicants greatly exceeds the number of available places for students. This is the case in many countries of continental Europe.

Students in much of Europe choose their field of specialization when they begin university study, unlike students in North America, who specialize later. Fields such as medicine, law, biology, dentistry, pharmacology, psychology and business administration are particularly popular and therefore harder to gain admittance to study.

In France, admission to the grandes écoles is obtained by competitive exams with a fixed, limited number of positions each year. Also, at the end of the first year of medical studies in universities, there is a competitive exam with a numerus clausus for determining which students are allowed to proceed to the second year; in later years of medical studies there is a competitive exam (concours de l'internat) for choosing medical specialties.