In the United States and Canada, an academic major (informally major) is the academic discipline to which an undergraduate student formally commits. A student who successfully completes the courses prescribed in an academic major qualifies for an undergraduate degree. The word "major" is also sometimes used administratively to refer to the academic discipline pursued by a graduate student or postgraduate student in a master's or doctoral program. The term may also apply to a focused field of an academic discipline that a student chooses at the doctoral studies level.

In the United States, in the second half of the 19th century, concentrated foci at the undergraduate level began to prosper and popularize, but the familiar term "major" did not appear until 1877 in a Johns Hopkins University catalogue. The major generally required 2 years of study. The minor, required one.Abbott Lawrence Lowell introduced the academic major system to Harvard University in 1910, during his presidency there. It required students to complete courses not only in a specialized discipline, but also in other subjects. Variations of this system are now definitive among tertiary education institutions in the United States and Canada.