Bill Clinton, the 42nd president of the United States, was impeached by the United States House of Representatives of the 105th United States Congress on December 19, 1998. The House adopted two articles of impeachment against Clinton, with the specific charges against Clinton being lying under oath and obstruction of justice. Two other articles had been considered but were rejected by the House vote.

Clinton's impeachment came after a formal House inquiry, which had been launched on October 8, 1998. The charges for which Clinton was impeached stemmed from a sexual harassment lawsuit filed against Clinton by Paula Jones. During pre-trial discovery in the lawsuit, Clinton gave testimony denying that he had engaged in a sexual relationship with White House intern Monica Lewinsky. The catalyst for the president's impeachment was the Starr Report, a September 1998 report prepared by Ken Starr, Independent Counsel, for the House Judiciary Committee. The Starr Report included details outlining a sexual relationship between Clinton and Lewinsky. Clinton was the second American president to be impeached, the first being Andrew Johnson, who was impeached in 1868.

The approved articles of impeachment would be submitted to the United States Senate on January 7, 1999. A trial in the Senate then began, with Chief Justice William Rehnquist presiding. On February 12, Clinton was acquitted on both counts as neither received the necessary two-thirds majority vote of the senators present for conviction and removal from office—in this instance 67 votes were needed. On Article One, 45 senators voted to convict while 55 voted for acquittal. On Article Two, 50 senators voted to convict while 50 voted for acquittal. Clinton remained in office for the remainder of his second term.

In 1994, Paula Jones filed a lawsuit accusing Clinton of sexual harassment when he was governor of Arkansas. Clinton attempted to delay a trial until after he left office, but in May 1997 the Supreme Court unanimously rejected Clinton's claim that the Constitution immunized him from civil lawsuits, and shortly thereafter the pre-trial discovery process commenced.

Separate from this, in January 1994, Attorney General Janet Reno appointed Robert B. Fiske as an Independent counsel to investigate the Whitewater controversy. In August of that year, Ken Starr was appointed to replace Fiske in this role.

In 1997, the first effort in Congress to start an impeachment against Clinton was launched by Republican Congressman Bob Barr.

In a January 17, 1998, sworn deposition, Clinton denied having a "sexual relationship", "sexual affair", or "sexual relations" with Lewinsky. His lawyer, Robert S. Bennett, stated with Clinton present that Lewinsky's affidavit showed there was no sex in any manner, shape or form between Clinton and Lewinsky. The Starr Report states that the following day, Clinton "coached" his secretary Betty Currie into repeating his denials should she be called to testify.

After rumors of the scandal reached the news, Clinton publicly said, "I did not have sexual relations with that woman, Miss Lewinsky." But months later, Clinton admitted his relationship with Lewinsky was "wrong" and "not appropriate". Lewinsky engaged in oral sex with Clinton several times.