The impeachment process against Richard Nixon was initiated by the United States House of Representatives on October 30, 1973, during the course of the Watergate scandal, when multiple resolutions calling for the impeachment of President Richard Nixon were introduced immediately following the series of high-level resignations and firings widely called the "Saturday Night Massacre". The House Committee on the Judiciary soon began an official investigation of the president's role in Watergate, and, in May 1974, commenced formal hearings on whether sufficient grounds existed to impeach Nixon of high crimes and misdemeanors under Article II, Section 4, of the United States Constitution. This investigation was undertaken one year after the United States Senate established the Select Committee on Presidential Campaign Activities to investigate the break-in at the Democratic National Committee headquarters at the Watergate office complex during the 1972 presidential election, and the Republican Nixon administration's attempted cover-up of its involvement; during those hearings the scope of the scandal became apparent and the existence of the Nixon White House tapes was revealed.

Richard Milhous Nixon was the 37th president of the United States, serving from 1969 to 1974. A member of the Republican Party, he previously served as a representative and senator from California and as the 36th vice president from 1953 to 1961 under President Dwight D. Eisenhower. His presidency saw the reduction of U.S. involvement in the Vietnam War, détente with the Soviet Union and China, the Apollo 11 Moon landing, and the establishment of the Environmental Protection Agency and Occupational Safety and Health Administration. Nixon's second term ended early when he became the only U.S. president to resign from office, as a result of the Watergate scandal.