A political prisoner is someone who is detained in prison or under house arrest because his or her political views do not agree with that of the ruling political establishment in a given country. In many cases, a veneer of legality is used to disguise the fact that someone is a political prisoner. Trumped-up criminal charges may have been used to imprison the political prisoner, or he or she may have been denied bail unfairly, denied parole when it would reasonably have been given to another prisoner, or special powers may be invoked by the judiciary. In the Soviet Union, dubious psychiatric diagnoses were sometimes used to confine political prisoners, and there have been allegations by some individuals that this is currently done in the US.

Who is and who is not regarded as a political prisoner depends very much on one's own political persuasion and on the prevailing political fashions. The list below contains some people who have been regarded as such by large numbers of people, but no definitive, objective list could ever be given.

Amnesty International campaigns for the release of "prisoners of conscience", which includes both political prisoners and those imprisoned for their religious beliefs. To reduce controversy, the organization's policy is to work only for prisoners who have not committed or advocated violence.

Night and Fog prisoners were political prisoners in Germany during World War II.

Examples of persons claimed to be political prisoners: