Prisoner abuse is the mistreatment of persons while they are under arrest or incarcerated. Prisoner abuse can include physical abuse, psychological abuse, sexual abuse, torture, or other acts such as refusal of essential medication, and it can be perpetuated by either fellow inmates or prison faculty.

Abuse of prisoners can include physical abuse, as well as psychological forms of harm including verbal abuse, sleep deprivation, white noise, pointless/absurd or humiliating instructions, recurrent exhaustive inspections and shakedowns, arbitrary strip searches, and denuding actions.

Prisoners are sometimes intentionally housed with inmates known to have raped other prisoners, or protection from known rapists may be purposely withheld from the prisoners. These practices create a very high incidence of rape in US prisons, which was the topic of the 2001 report No Escape from Human Rights Watch.

The experience of forced strip searches can be experienced as a traumatic event similarly to that of rape, especially when combined with habitual body cavity searches. The prevalence of CCTV in modern correctional facilities and the generally indiscreet nature of strip searches, often with a number of prison guards observing, usually adds to the experienced humiliation. Strip searches are often arbitrarily used under various pretences, when the actual ambition is to assert control and predominance as well as to intimidate the subjected prison inmates.

Torture of prisoners includes any act, whether physical or psychological, which is deliberately done to inflict sensations of pain upon a person under the actor's custody or physical control. This form of prisoner abuse is usually exerted to extract information, but also as means of intimidation, attrition or punishment.

"Enhanced interrogation" is a euphemism for U.S. torture methods implemented in the war on terror purportedly needed to extract information from detainees. Examples include use of stress positions, sleep deprivation, starvation, thirst, and sexual humiliation.

During the early stages of the Iraq War, members of the United States Army and the Central Intelligence Agency committed a series of human rights violations and war crimes against detainees in Abu Ghraib prison in Iraq. These abuses included physical abuse, sexual humiliation, physical and psychological torture, and rape, as well as the killing of Manadel al-Jamadi and the desecration of his body. The abuses came to public attention with the publication of photographs by CBS News in April 2004, causing shock and outrage and receiving widespread condemnation within the United States and internationally.

The George W. Bush administration stated that the abuses at Abu Ghraib were isolated incidents and not indicative of U.S. policy. This was disputed by humanitarian organizations including the Red Cross, Amnesty International, and Human Rights Watch, who claimed the abuses were part of a pattern of torture and brutal treatment at American overseas detention centers, including those in Iraq, in Afghanistan, and at Guantanamo Bay (GTMO). After 36 prisoners were killed at Abu Ghraib in insurgent mortar attacks, the United States was further criticized for maintaining the facility in a combat zone. The International Committee of the Red Cross reported that most detainees at Abu Ghraib were civilians with no links to armed groups.