Academic freedom is the right of a teacher to instruct and the right of a student to learn in an academic setting unhampered by interference. It may also include the right of academics to engage in social and political criticism.

Academic freedom is often premised on the conviction that freedom of inquiry by faculty members is essential to the mission of the academy as well as the principles of academia, and that scholars should have freedom to teach or communicate ideas or facts (including those that are inconvenient to external political groups or to authorities) without the fear of being repressed, losing their job or being imprisoned. While the core of academic freedom covers scholars acting in an academic capacity (as teachers or researchers expressing strictly scholarly viewpoints), an expansive interpretation extends these occupational safeguards to scholars' speech on matters outside their professional expertise.

Academic tenure protects academic freedom by ensuring that teachers can be fired only for causes such as gross professional incompetence or behavior that evokes condemnation from the academic community itself. The academic community pressuring scholars can reduce academic freedom.

Historically, academic freedom emerged tentatively, as academics in medieval and early modern Europe could face repression for acting in ways considered objectionable by religious authorities or by governments. Scholars tend to link the institutionalization of academic freedom to the rise of the modern research university and the Humboldtian model of higher education from the 19th century. By one estimate, academic freedom has substantially increased worldwide since the 1960s. Academic freedom is more likely in liberal democratic states, while it is more heavily constrained in authoritarian states, illiberal states, and states embroiled in military conflict. Since 2013, while some countries have seen improvements to academic freedom, the overall trend is towards reductions in freedom.

A minimal definition of academic freedom is that a teacher has a right to instruct, and a student has a right to learn in an academic setting unhampered by interference. Other definitions include the right of teachers to engage in social and political criticism.

A broader definition of academic freedom incorporates individual, extramural and institutional components. Under this broader definition, an academic has freedom of expression without government interference, but this freedom is circumscribed by academic expertise and position. Academic freedom of speech is therefore narrower than a general freedom of speech. For example, a non-academic has the freedom of speech to criticize the efficacy of vaccines, but only has academic freedom to do so if they possess the prerequisite academic qualifications to do so. Unlike public speech, academic speech is also subject to quality controls by academic peers, for example through peer review.

Universities UK has defined academic freedom as "protecting the intellectual independence of academics to question and test received views and wisdom, and to put forward new ideas and controversial or unpopular opinions, without placing themselves in danger of losing their jobs or privileges", while the American Federation of Teachers has seen it as "based on the idea that the free exchange of ideas on campus is essential to good education". Norwegian education sees it as a guarantee that research and teaching is "intellectually and morally independent of all political and economic interests", leading to openness, free enquiry and debate.

The laissez-faire approach of unaccountable academic freedom is contrasted with democratic accountability of academia.