Robert Carl "Bud" McFarlane (born July 12, 1937) is a retired Marine Corps officer who serves as National Security Advisor to President of the United States Ronald Reagan from 1983 through 1985.

After a career in the Marines, McFarlane becomes part of the Reagan administration and is a leading architect of the Strategic Defense Initiative (SDI) for defending the United States against missile attack.

Subsequently, he is involved in, and pleads guilty to charges for actions related to, the Iran-Contra affair, but receives a pardon from President George H.W. Bush.