Generally, tenure is the holding of a secure position within an educational institution or system, although it can also refer to an individual's length of service in a particular position or system. Usually associated with appointments of university or college faculty members, the granting of tenure by the institution signifies that the individual has an ongoing appointment that may be terminated only through resignation, retirement, or dismissal for good reasons as established by a proper hearing.

University and college professors consider tenure essential because it enables the holder to exercise free but responsible criticism of his institution and all aspects of society without fear of dismissal. Among the more widely publicized tenure cases in Canada was that of Frank Underhill, a history professor at University of Toronto, whose resignation was demanded by the university's board of governors in 1941 because of his "ill-considered" statements about Canada's changing relationships with Britain and the US. Despite considerable controversy, Underhill remained, signalling to the Canadian academic community and the public that academic tenure continued to be in effect, even in wartime.

Scholars note that academic tenure is essential for sustaining intellectual freedom and dissent especially in institutions that rely on financial support from governments and private donors. Tenure gives academics the freedom to follow research agendas on long-term problems and allows them to publish critical conclusions. Some scholars note that the academic enterprise is a partnership between institutional administrators and tenured faculty members. Despite the strong arguments set forth by academics in defence of a system of tenure, it has been a point of discussion and debate. Some argue that tenure permits senior professors to become unproductive and prevents young faculty members from being employed in full-time positions.

The effects of tenure policy are not likely to be as harmful in a period when universities and colleges are expanding in number and size (eg, in the 1950s and 1960s in Canada) as in a period of limited growth or retrenchment (1970s, 1980s and 2000s). To counter these effects, some people have supported the elimination of tenured positions, the introduction of limited contracts or post-tenure review processes. The justification of tenure continues to be part of ongoing discussions on the re-structuring of the academy.

See also Academic Freedom.