Clark MacGregor (July 12, 1922 – February 10, 2003) was an American politician and Republican U.S. Representative from Minnesota's 3rd Congressional District for five terms from 1961 to 1971.

Senator from Minnesota in 1970, losing to former Democratic Vice President Hubert Humphrey.

[6][7] MacGregor was Assistant to Richard Nixon for congressional relations in 1970, Counsel to the President on congressional relations (1971–1972), Chairman of the Committee to Re-elect the President (July to November 1972) following John Mitchell's resignation from the position in the Watergate political scandal.

In October 1972, as the reporting of Bob Woodward and Carl Bernstein began to piece together the extent of the spying and sabotage program of the Nixon campaign, MacGregor in a press conference attacked The Washington Post for allegedly "Using innuendo, third-person hearsay, unsubstantiated charges, anonymous sources, and huge scare headlines ... maliciously ... to give the appearance of a direct connection between the White House and the Watergate -- a charge the Post knows -- and a half dozen investigations have found -- to be false.

He continued to live in Washington, D.C., worked for United Technologies Corporation, and was on the boards of the National Symphony Orchestra and the Wolf Trap Foundation.