The Tenure of Office Act was a United States federal law, in force from 1867 to 1887, that was intended to restrict the power of the president to remove certain office-holders without the approval of the U.S. Senate. The law was enacted March 2, 1867, over the veto of President Andrew Johnson. It purported to deny the president the power to remove any executive officer who had been appointed by the president with the advice and consent of the Senate, unless the Senate approved the removal during the next full session of Congress.

Johnson's attempt to remove Secretary of War Edwin Stanton from office without the Senate's approval led to the impeachment of Johnson in early 1868 for violating the act.

The act was significantly amended by Congress on April 5, 1869, under President Ulysses S. Grant. Congress repealed the act in its entirety in 1887, 20 years after the law was enacted. While evaluating the constitutionality of a similar law in Myers v. United States (1926), the Supreme Court stated that the Tenure of Office Act was likely invalid.

The notion of the United States Senate advising and consenting the removal of Cabinet members to the same of the appointments were considered during the 1st United States Congress. The vote was tied with 9 in favor and 9 against on July 18, 1789. Vice President John Adams, with his first tie-breaking vote, voted against the bill, defeating it.

The Constitution adopted by the Confederate States of America was more explicit on the point, providing in Article II, Section 2, Clause 3 thereof, that "The principal officer in each of the Executive Departments, and all persons connected with the diplomatic service, may be removed from office at the pleasure of the President. All other civil officers of the Executive Departments may be removed at any time by the President, or other appointing power, when their services are unnecessary, or for dishonesty, incapacity, inefficiency, misconduct, or neglect of duty; and when so removed, the removal shall be reported to the Senate, together with the reasons therefor."

In the post-Civil War political environment, President Johnson, a Democrat who had served as Abraham Lincoln's second vice president, endorsed the quick re-admission of the Southern secessionist states. The two-thirds Republican majorities of both houses of Congress passed laws over Johnson's vetoes, establishing a series of five military districts overseeing newly created state governments. This "Congressional Reconstruction" was designed to create local civil rights laws to protect newly freed slaves; to protect and patrol the area; to ensure the secessionist states would show some good faith before being readmitted; to ensure Republican control of the states; and, arguably, to inflict some punishment on the secessionists. States would be readmitted gradually.

Overpowered politically, Johnson could apply the sole check to the Congressional Reconstruction plan of his control (as commander-in-chief) of the military, which would be the primary institution enforcing the plan's provisions. Even Johnson's control of the military was inhibited by the fact that his Secretary of War, Edwin Stanton, was a staunch Radical Republican who supported Congressional Reconstruction in full. This further set Johnson against the Republican-controlled Congress, with Johnson wanting to remove Stanton from office and Congress wanting to keep him in place.

George F. Edmunds played an important role in the passage of the Tenure of Office Act in the Senate.