Robert Carl "Bud" McFarlane (July 12, 1937 – May 12, 2022) was an American Marine Corps officer who served as National Security Advisor to President Ronald Reagan from 1983 to 1985. Within the Reagan administration, McFarlane was a leading architect of the Strategic Defense Initiative, a project intended to defend the US from Soviet ballistic missile attacks. He resigned as National Security Adviser in late 1985 because of disagreements with other administration figures but remained involved in negotiations with Iran and with Hezbollah.
McFarlane was a central figure in the Iran–Contra affair, an operation in which the Reagan administration funneled weapons to Iran and diverted the profits to illegally fund right-wing rebels in Nicaragua. When the scheme came to light, administration officials implemented a plan to insulate Reagan and senior officials by focusing blame on McFarlane. He ultimately pleaded guilty to four misdemeanor counts and admitted that he had hidden information about the Reagan administration's support of the Contras from Congress.