A graduate school or "grad school" is a school that awards advanced degrees, with the general requirement that students must have earned an undergraduate (bachelors) degree. Many universities award graduate degrees; a graduate school is not necessarily a separate institution. A graduate school experience often involves a significant component of original research, including the writing and defense of a thesis or dissertation. The term "graduate school" is primarily North American, the term not being used in the United Kingdom. It also does not usually refer to medical school (students are called "medical-students") and only occasionally refers to law school or business school.

Those attending graduate schools are called "graduate students". Degrees awarded by graduate schools include master's degrees, doctoral degrees (Ph.D.s), and other postgraduate qualifications such as a graduate certificates, as well as some professional degrees.