The oath of office is the oath made by the president of the United States before assuming the presidency as required by the U.S. Constitution. The oath is printed in the Constitution in article II, section 1, clause 8 in the description of the duties of the executive branch of U.S. government.
The president recites the oath with his hand on the Bible as a part of the inauguration ceremony. The chief justice of the Supreme Court traditionally administers the oath to the president. This ceremony is usually well attended by the public. The oath requires the president to swear that he will faithfully execute the office of the president and will also preserve, protect and defend the U.S. Constitution.
The framers of the Constitution thought it vital that the president have a separate and distinct oath of office. Constitutional scholars suggest the framers also sought to limit the power of the president by phrasing the oath in this way and by aligning the president as the upholder and not the creator of the Constitution.
In addition to these celebrated presidential inaugurations, there are also more somber occasions where the vice president is sworn in after the death of the president. In U.S. history, eight vice presidents have been sworn in during a more private oath ceremony immediately following the death of the president, and one vice president was sworn in after a presidential resignation.