Abdurahman Ahmed Said Khadr (Arabic: عبد الرحمن أحمد سعيد خضر, ʿAbd ar-Raḥman Ḫaḍr; born 1982) is a Canadian citizen who was held as an enemy combatant in extrajudicial detention by the United States at the Guantanamo Bay detainment camps, in Cuba, after being detained in 2002 in Afghanistan under suspicion of connections to Al-Qaeda. He later claimed to have been an informant for the CIA. The agency declined to comment on this when asked for confirmation by the United States' PBS news program Frontline. He was released in the fall of 2003 and ultimately returned to Canada.

He is the third child and second son of Ahmed Khadr, an Egyptian immigrant who was known for ties to al-Qaeda, and his wife Maha el-Samnah, who is Palestinian. His younger brother Omar Khadr was captured by United States forces separately at the age of 15 in Afghanistan in 2002 during a firefight; he was held in Guantanamo for several years but transferred in September 2012 to Canadian custody.

Abdurahman Khadr was born in Manama, Bahrain in 1982, the son of Ahmed Khadr and Maha el-Samnah. Egyptian and Palestinian immigrants to Canada who had become naturalized citizens there, and met and married. His father went to graduate school in Ottawa, and then started working in Bahrain. Ahmed Khadr visited Pakistan after the Soviet invasion of Afghanistan in the early 1980s, and brought his family to Pakistan in 1985. There he worked for charities assisting Afghan refugees.

In his youth, Abdurahman Khadr was known as the "problem child" in the family, frequently running away and getting in trouble, refusing to follow rules, drinking alcohol and smoking cigarettes. He had an older sister and brother, three younger brothers and a younger sister.

In 1994, at the age of 12, Khadr was sent to Khalden training camp along with his older brother Abdullah, where he was given the alias Osama. The two brothers fought constantly at the camp, and one day their argument became so heated that they pointed guns at each other, screaming with fury. A trainer stepped between them. In 1997, a dispute between the brothers was mediated by the older Abu Laith al-Libi, who earned their confidence and respect telling them about the city of Dubai and imported Ferraris; he was later described as "really cool" by Abdurahman.

While the family was briefly living in Nazim Jihad with Osama bin Laden's family in 1998, Abdurahman became close friends with Abdulrahman bin Laden, who was near his age and the only child in the group to have his own horse, a fine Arabian. Abdurahman successfully persuaded his father to buy him a horse, too. Once, when the two horses fought, the young bin Laden pointed a gun at Khadr, yelling at him to stop the fight before his prized Arabian was killed.

When the family was leaving the compound, Abdurahman and his brother Abdullah fought over seating in the car. Their mother ended up asking bin Laden if he could take care of the troublesome Abdurahman since "she could not control him. He grudgingly agreed to look after the youth until his father returned. But, the next day bin Laden told Abdurahman that it would not work, and he asked Saif al-Adel to take the 16-year-old to the bus station so he could catch up with his family en route back to Peshawar."

The following year, at age 13, Abdurahman was sent to Jihad Wel al-Farouq for seven days; US officials have said the training camp was run by al-Qaeda personnel to train their militants. On August 20, 1998, the Al Farouq training camp was bombed by American cruise missiles and Amr Hamed, a friend of Khadr's, was killed. Khadr later said that as a youth, he had hated the Americans for killing his friend.