A graduate school or "grad school" is a school that awards advanced degrees, with the general requirement that students must have earned an undergraduate (bachelor's) degree. Many universities award graduate degrees; a graduate school is not necessarily a separate institution. Original research experience is often a significant component of graduate studies, including the writing and defense of a thesis or dissertation. The term "graduate school" is primarily North American, 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 graduate certificates and professional degrees.

Although graduate-school programs are distinct experiences from undergraduate-degree programs, graduate instruction (in Australia, the United States, and other countries) is often offered by some of the same senior faculty and departments as taught undergraduate courses. Unlike in undergraduate programs, it is rarer for graduate students to take coursework outside their specific field of study at the Master's level. At the Ph.D. level, though, it is quite common to take courses from a wider range of study, for which some fixed portion of coursework is typically required to be taken from outside the department and college of the degree-seeking candidate, to broaden the research abilities of the student. Some institutions designate separate graduate versus undergraduate faculty and denote other divisions (often called School of X, e.g., diplomacy) - Top Graduate School Rankings