Julian Paul Assange (/əˈsɑːnʒ/ ^ⓘ ə-SAHNZH; né Hawkins; born 3 July 1971) is an Australian editor, publisher, and activist who founded WikiLeaks in 2006. He came to international attention in 2010 after WikiLeaks published a series of leaks from Chelsea Manning, a United States Army intelligence analyst: footage of a U.S. airstrike in Baghdad showing probable war crimes committed by the US army, U.S. military logs from the Afghanistan and Iraq wars, and U.S. diplomatic cables. Assange has won over two dozen awards for publishing and human rights activism.

Assange was raised in various places around Australia until his family settled in Melbourne in his middle teens. He became involved in the hacker community and was convicted for hacking in 1996. Following the establishment of WikiLeaks, Assange was its editor when it published the Bank Julius Baer documents, footage of the 2008 Tibetan unrest, and a report on political killings in Kenya with The Sunday Times. Publication of the leaks from Manning started in February 2010.

In November 2010 Sweden wished to question Assange in an unrelated police investigation and sought to extradite him from the UK. In June 2012, Assange breached his bail and took refuge in the Embassy of Ecuador in London. He was granted asylum by Ecuador in August 2012 on the grounds of political persecution and fears he might be extradited to the United States. Swedish prosecutors dropped their investigation in 2019. In 2013, Assange launched the WikiLeaks Party and unsuccessfully stood for the Australian Senate while remaining in the Ecuadorian embassy. During the 2016 U.S. election campaign, WikiLeaks published confidential Democratic Party emails, showing that the party's national committee favoured Hillary Clinton over Bernie Sanders in the primaries and it had sought to undermine the Sanders campaign. In March 2017, WikiLeaks published a series of documents which detailed the CIA's tools for hacking into smartphones and other internet devices, after which senior CIA officials discussed potentially kidnapping or assassinating Assange.

On 11 April 2019, Assange's asylum was withdrawn following a series of disputes with Ecuadorian authorities; the police were invited into the embassy and he was arrested. He was found guilty of breaching the United Kingdom Bail Act and sentenced to 50 weeks in prison. The U.S. government unsealed an indictment charging Assange with conspiracy to commit computer intrusion related to the leaks provided by Manning. In May 2019 and June 2020, the U.S. government unsealed new indictments against Assange, charging him with violating the Espionage Act of 1917 and alleging he had conspired with hackers. The key witness for the new indictment, whom the justice department had given immunity in return for giving evidence, stated in 2021 that he had fabricated his testimony. Critics have described these charges as an unprecedented challenge to press freedom with potential implications for investigative journalism worldwide. Assange was incarcerated in HM Prison Belmarsh in London from April 2019 to June 2024, as the U.S. government's extradition effort was contested in the UK courts.

In 2022, the incoming Australian Labor government of Anthony Albanese reversed the position of previous governments and began to lobby for Assange's release. In 2024, following a High Court ruling that granted Assange a full appeal to extradition, Assange and his lawyers negotiated a deal with US prosecutors. Assange agreed to a plea deal in which he pleaded guilty in Saipan, Northern Mariana Islands, to an Espionage Act charge of conspiring to obtain and disclose classified U.S. national defence documents in return for a sentence of time served. Following the hearing Assange flew to Australia, arriving on 26 June 2024.

Assange was born Julian Paul Hawkins on 3 July 1971 in Townsville, Queensland, to Christine Ann Hawkins, a visual artist, and John Shipton, an anti-war activist and builder. The couple separated before their son was born. When Julian was a year old his mother married Brett Assange, an actor with whom she ran a small theatre company and whom Julian Assange regards as his father (choosing Assange as his surname). Christine and Brett Assange divorced around 1979. Christine then became involved with Leif Meynell, also known as Leif Hamilton, whom Julian Assange later described as "a member of an Australian cult" called The Family. Meynell and Christine Assange separated in 1982.

Julian Assange lived in more than thirty Australian towns and cities during his childhood. He attended several schools, including Goolmangar Primary School in New South Wales (1979–1983) and Townsville State High School in Queensland as well as being schooled at home. In his mid-teens, he settled with his mother and half-brother in Melbourne. He moved in with his girlfriend at age 17.

Assange studied programming, mathematics, and physics at Central Queensland University (1994) and the University of Melbourne (2003–2006), but did not complete a degree. Assange started the Puzzle Hunt tradition at the University of Melbourne, which was modelled after the MIT Mystery Hunt. He was involved in the Melbourne rave scene, and assisted in installing an internet kiosk at Ollie Olsen's club night called "Psychic Harmony", which was held at Dream nightclub in Carlton (later called Illusion). Assange's nickname at the raves was "Prof".