The impeachment of Andrew Johnson was initiated on February 24, 1868, when the United States House of Representatives passed a resolution to impeach Andrew Johnson, the 17th president of the United States, for "high crimes and misdemeanors". The alleged high crimes and misdemeanors were afterwards specified in eleven articles of impeachment adopted by the House on March 2 and 3, 1868. The primary charge against Johnson was that he had violated the Tenure of Office Act. Specifically, that he had acted to remove from office Edwin Stanton and to replace him with Brevet Major General Lorenzo Thomas as secretary of war ad interim. The Tenure of Office Act had been passed by Congress in March 1867 over Johnson's veto with the primary intent of protecting Stanton from being fired without the Senate's consent. Stanton often sided with the Radical Republican faction and did not have a good relationship with Johnson.

In the United States, federal impeachment is the process by which the House of Representatives charges the president, vice president, or another civil federal officer for alleged misconduct. The House can impeach an individual with a simple majority of the present members or other criteria adopted by the House according to Article One, Section 2, Clause 5 of the U.S. Constitution.