Cage International is a London-based human rights advocacy organisation which aims to empower communities impacted by the war on terror. Cage highlights and campaigns against state policies developed as part of the war on terror. The organisation was formed to raise awareness of the plight of detainees held at Guantánamo Bay and elsewhere and related human rights concerns, and has worked closely with former detainees held by the United States and campaigns on behalf of current detainees held without trial. Cage was formerly known as Cageprisoners, and was ordinarily styled as "CAGE".

CAGE has faced ongoing criticism due to the people it works with and its public statements. Critics point out its links to Moazzam Begg, Anwar al-Awlaki and Jihadi John, and argue that the group sometimes seems to support or excuse extremist figures instead of clearly rejecting them.

Cage offers support to those denied due process regarding terrorism offences through casework, advocacy and research. The organisation also documents miscarriages of justice. Cage has developed the trust of Muslims who have been subjected to torture, harassment and other abuses, by informing them of their rights and putting them in touch with lawyers. Cage has also campaigned for the release of hostages held by the Islamic State.

Cage's outreach director, Moazzam Begg, is a Briton from Birmingham who was held for three years by the United States government in extrajudicial detention as a suspected enemy combatant at Bagram in Afghanistan, and the Guantánamo Bay detainment camp in Cuba. He was released without charge in 2005. He has worked to represent detainees still held at Guantánamo, as well as to help former detainees re-integrate into society. He has also been working with governments to persuade them to accept non-national former detainees, some of whom have been refused entry by their countries of origin. Begg has played a crucial role in proving UK complicity in US imprisonment and torture in Bagram and elsewhere, and aided detainees seeking admission and compensation from the UK government.

Between 2007 and 2014, the Joseph Rowntree Charitable Trust gave grants to Cage totalling £271,250. In a similar period, the Roddick Foundation, founded by Anita Roddick, gave grants totalling £120,000. In 2015, following pressure from the UK government's Charity Commission, both entities agreed to cease funding Cage. The Charity Commission had said that "Given the nature of [Cage’s] work, and the controversy it has attracted, the Charity Commission has been concerned that such funding risked damaging public trust and confidence in charity".

The Rowntree Trust said the Charity Commission had applied "acute regulatory pressure" and had threatened to institute an exhaustive investigation into the Trust if it refused to stop funding CAGE. The Trust stated that "We believe (Cage) has played an important role in highlighting the ongoing abuses at Guantanamo Bay and at many other sites around the world, including many instances of torture". Cage said that the majority of their income comes from private individuals and that the group "would continue its work regardless of the criticism levelled at it ... even though we aren't a proselytizing organisation, we are a Muslim response to a problem that largely affects Muslims".

In October 2015, following an application for judicial review by Cage, the Charity Commission changed its position and said it would not in future interfere in the discretion of charities to choose to fund Cage. The judicial review heard evidence that Theresa Villiers, a British Cabinet Minister, and US intelligence had both applied pressure on the charity commission to investigate Cage, with US intelligence agents describing Cage as a "jihadist front".

Cage's website was launched in October 2003. It was among the leading organisations which worked on publicising the names of the detainees at Guantanamo. Due to the U.S. government's refusal to publish a list of names until a Freedom of Information lawsuit in 2006, it published names, photos and other information about detainees obtained from detainees' families. The U.S. government's refusal impeded the efforts of lawyers who had wished to represent the detainees there. Cage was formerly Cageprisoners Ltd, and is sometimes styled as "CAGE".