The IranContra affair (Persian: -, Spanish: Caso IrnContra), often referred to as the IranContra scandal, the McFarlane affair (in Iran), or simply IranContra, was a political scandal in the United States that occurred during the second term of the Reagan administration. Between 1981 and 1986, senior administration officials secretly facilitated the sale of arms to Iran, which was the subject of an arms embargo. The administration hoped to use the proceeds of the arms sale to fund the Contras, a right-wing rebel group, in Nicaragua. Under the Boland Amendment, further funding of the Contras by the government had been prohibited by Congress.

The official justification for the arms shipments was that they were part of an operation to free seven American hostages being held in Lebanon by Hezbollah, an Islamist paramilitary group with Iranian ties connected to the Islamic Revolutionary Guard Corps. The idea to exchange arms for hostages was proposed by Manucher Ghorbanifar, an expatriate Iranian arms dealer. Some within the Reagan administration hoped the sales would influence Iran to get Hezbollah to release the hostages.

In late 1985, Lieutenant Colonel Oliver North of the National Security Council diverted a portion of the proceeds from the Iranian weapon sales to fund the Contras, a group of anti-Sandinista rebels, in their insurgency against the socialist government of Nicaragua. North later claimed that Ghorbanifar had given him the idea for diverting profits from TOW and HAWK missile sales to Iran to the Nicaraguan Contras. While President Ronald Reagan was a vocal supporter of the Contra cause, the evidence is disputed as to whether he personally authorized the diversion of funds to the Contras. Handwritten notes taken by Defense Secretary Caspar Weinberger on 7 December 1985 indicate that Reagan was aware of potential hostage transfers with Iran, by Israel, as well as the sale of HAWK and TOW missiles to "moderate elements" within that country. Weinberger wrote that Reagan said "he could answer charges of illegality but he couldn't answer charge [sic] that 'big strong President Reagan passed up a chance to free hostages.'" After the weapon sales were revealed in November 1986, Reagan appeared on national television and stated that the weapons transfers had indeed occurred, but that the United States did not trade arms for hostages. The investigation was impeded when large volumes of documents relating to the affair were destroyed or withheld from investigators by Reagan administration officials. On 4 March 1987, Reagan made a further nationally televised address, taking full responsibility for the affair and stating that "what began as a strategic opening to Iran deteriorated, in its implementation, into trading arms for hostages".The affair was investigated by the U.S. Congress and by the three-person, Reagan-appointed Tower Commission. Neither investigation found evidence that President Reagan himself knew of the extent of the multiple programs. Additionally, United States Deputy Attorney General Lawrence Walsh was appointed Independent Counsel in December 1986 to investigate possible criminal actions by officials involved in the scheme. In the end, several dozen administration officials were indicted, including then-Secretary of Defense Caspar Weinberger. Eleven convictions resulted, some of which were vacated on appeal.The rest of those indicted or convicted were all pardoned in the final days of the presidency of George H. W. Bush, who had been Vice President at the time of the affair. Former Independent Counsel Walsh noted that in issuing the pardons, Bush appeared to have been preempting being implicated himself by evidence that came to light during the Weinberger trial, and noted that there was a pattern of "deception and obstruction" by Bush, Weinberger and other senior Reagan administration officials. Walsh submitted his final report on August 4, 1993, and later wrote an account of his experiences as counsel, Firewall: The Iran-Contra Conspiracy and Cover-Up.

Oliver Laurence North (born October 7, 1943) is an American political commentator, television host, military historian, author, and retired United States Marine Corps lieutenant colonel.

A veteran of the Vietnam War, North was a National Security Council staff member during the Iran–Contra affair, a political scandal of the late 1980s. It involved the illegal sale of weapons to the Khomeini regime of the Islamic Republic of Iran to encourage the release of American hostages then held in Lebanon. North formulated the second part of the plan, which was to divert proceeds from the arms sales to support the Contra rebel groups in Nicaragua, sales which had been specifically prohibited under the Boland Amendment. North was granted limited immunity from prosecution in exchange for testifying before Congress about the scheme. He was initially convicted on three felony charges, but the convictions were vacated and reversed and all charges against him dismissed in 1991.

North unsuccessfully ran for the U.S. Senate seat held by Chuck Robb from Virginia in 1994, receiving 43% of the vote. He then hosted a talk show on Radio America from 1995 to 2003, and hosted War Stories with Oliver North on Fox News from 2001 to 2016. In May 2018, North was elected as president of the National Rifle Association. On April 27, 2019, he resigned amidst a dispute with the organization's chief executive Wayne LaPierre, and was succeeded by Carolyn D. Meadows.