A master's degree is a postgraduate academic degree awarded after the completion of an academic program of one to six years in duration.

In the recently standardized European system of higher education diplomas, it corresponds to a one to two year (60 to 120 ECTS credits) postgraduate program undertaken after at least three years of undergraduate studies. It provides higher qualification for employment or prepares for doctoral studies. In the USA and Canada, a master's degree entails a one- or two–year course in which students would normally enroll after completing a bachelor's degree.

However, in some European countries, a magister is a first degree and may be considered equivalent to a modern (standardized) master's degree (e.g., the German university Diplom/Magister, or the similar 5-year diploma awarded in several subjects in Greek, Spanish, Italian, and other universities and polytechnics). In the Francophone countries, a DEA is the postgraduate degree and considered equivalent to the master's degree (e.g, In France, the French-Speaking Switzerland and Belgium a DEA is 1-2 years degree taken after the Licence).

The master of arts (magister artium), master of science (magister scientiæ) and Master of Science in Law degrees are the basic degree types in most subjects, and they may be course-based, research-based, or (more typically) a mixture of the two. A dissertation may or may not be required, depending on the program. There are also degrees of the same level, such as engineer's degrees, which have different names for historical reasons.

Admission to a master's program normally requires holding a bachelor's degree (in the United Kingdom an 'honours' bachelor degree), although relevant work experience may qualify a candidate. Progressing to a doctoral program sometimes requires that the candidate first earn a master's degree. In some fields or postgraduate programs, work on a doctorate begins immediately after the bachelor's degree, but the master's may be earned along the way, as a result of the successful completion of coursework and certain examinations. In some cases the student's bachelor's degree must be in the same subject as the intended master's degree, or in a closely allied discipline; in others, the subject of the bachelor's degree is unimportant.

There has recently been an increase in programs leading to these degrees in the United States; more than twice as many such degrees are now awarded as compared to the 1970s. Some university programmes provide for a joint bachelor's and master's degree after four or five years.