The Afghan War documents leak, also called the Afghan War Diary, is the disclosure of a collection of internal U.S. military logs of the War in Afghanistan, which were published by WikiLeaks on 25 July 2010. The logs consist of over 91,000 Afghan War documents, covering the period between January 2004 and December 2009. Most of the documents are classified secret. As of 28 July 2010, only 75,000 of the documents have been released to the public, a move which WikiLeaks says is "part of a harm minimization process demanded by [the] source". Prior to releasing the initial 75,000 documents, WikiLeaks made the logs available to The Guardian, The New York Times and Der Spiegel in its German and English online edition, which published reports in line with an agreement made earlier the same day, 25 July 2010.The leak, which is considered to be one of the largest in U.S. military history, revealed information on the deaths of civilians, increased Taliban attacks, and involvement by Pakistan and Iran in the insurgency. WikiLeaks says it does not know the source of the leaked data. The three outlets which had received the documents in advance, The New York Times, The Guardian, and Der Spiegel, have all concluded that they are genuine when compared with independent reports.The New York Times described the leak as "a six-year archive of classified military documents [that] offers an unvarnished and grim picture of the Afghan war". The Guardian called the material "one of the biggest leaks in U.S. military history ... a devastating portrait of the failing war in Afghanistan, revealing how coalition forces have killed hundreds of civilians in unreported incidents, Taliban attacks have soared and NATO commanders fear neighbouring Pakistan and Iran are fuelling the insurgency". Der Spiegel wrote that "the editors in chief of Spiegel, The New York Times and The Guardian were 'unanimous in their belief that there is a justified public interest in the material'."Some time after the first dissemination by WikiLeaks, the U.S. Justice Department considered using the U.S. Espionage Act of 1917 to prevent WikiLeaks from posting the remaining 15,000 secret war documents it claimed to possess.

WikiLeaks () is an international non-profit organisation that publishes news leaks and classified media provided by anonymous sources. Its website, initiated in 2006 in Iceland by the organisation Sunshine Press, stated in 2015 that it had released online 10 million documents in its first 10 years. Julian Assange, an Australian Internet activist, is generally described as its founder and director. Since September 2018, Kristinn Hrafnsson has served as its editor-in-chief.The group has released a number of prominent document caches. Early releases included documentation of equipment expenditures and holdings in the Afghanistan war, a report about a corruption investigation in Kenya, and an operating procedures manual for the U.S. prison at Guantanamo Bay, Cuba. In April 2010, WikiLeaks released the Collateral Murder footage from the 12 July 2007 Baghdad airstrike in which Iraqi Reuters journalists were among several civilians killed. Other releases in 2010 included the Afghan War Diary and the "Iraq War Logs". The latter release allowed the mapping of 109,032 deaths in "significant" attacks by insurgents in Iraq that had been reported to Multi-National Force – Iraq, including about 15,000 that had not been previously published. In 2010, WikiLeaks also released classified diplomatic cables that had been sent to the US State Department. In April 2011, WikiLeaks began publishing 779 secret files relating to prisoners detained in the Guantanamo Bay detention camp. In 2012, WikiLeaks released the "Syria Files," over two million emails sent by Syrian politicians, corporations and government ministries. In 2015, WikiLeaks published Saudi Arabian diplomatic cables, documents detailing spying by the U.S. National Security Agency on successive French presidents, and the intellectual property chapter of the Trans-Pacific Partnership, a controversial international trade agreement which had been negotiated in secret.During the 2016 U.S. presidential election campaign, WikiLeaks released emails and other documents from the Democratic National Committee and from Hillary Clinton's campaign manager, John Podesta, showing that the party's national committee favoured Clinton over her rival Bernie Sanders in the primaries, leading to the resignation of DNC chairwoman Debbie Wasserman Schultz and an apology to Sanders from the DNC. These releases caused significant harm to the Clinton campaign, and have been attributed as a potential contributing factor to her loss in the general election against Donald Trump. The U.S. intelligence community expressed "high confidence" that the leaked emails had been hacked by Russia and supplied to WikiLeaks. WikiLeaks said that the source of the documents was not Russia or any other state. During the campaign, WikiLeaks promoted conspiracy theories about Hillary Clinton and the Democratic Party.In 2016, WikiLeaks released nearly 300,000 emails it described as coming from Turkey's ruling Justice and Development Party, later found to be taken from public mailing archives, and rereleased over 50,000 emails from the Turkish Minister of Energy and Natural Resources. In 2017, WikiLeaks published internal CIA documents describing tools used by the agency to hack devices including mobile phones and routers. In 2019, WikiLeaks published over 30,000 files as part of the Fishrot Files, exposing corruption at SAMHERJI, a multinational fishing company based in Iceland. In October 2021, WikiLeaks' secure chat stopped working and in February 2022 their submission system and email server went offline.

WikiLeaks has drawn criticism for its absence of whistleblowing on or criticism of Russia, and for criticising the Panama Papers' exposé of businesses and individuals with offshore bank accounts. The organisation has additionally been criticised for inadequately curating its content and violating the personal privacy of individuals. WikiLeaks has, for instance, revealed Social Security numbers, medical information, credit card numbers and details of suicide attempts.