The term “designated survivor” is used in a variety of ways, but in American politics, it refers to a member of the Presidential line of succession who remains in a secure and distant spot when the other members of the line of succession are gathered together in the same location. Designated survivors are used during the State of the Union Address and also at Presidential inaugurations, and at other events where all of the people in the Presidential line of succession might be reasonably expected to gather.

The idea behind the designated survivor is that in the event of a catastrophic event, at least one person would be around to take on the mantle of the Presidency. This concept evolved during the Cold War, when the American government was concerned about the possibility of a nuclear attack which could wipe out all of those present at a major event or meeting. Since there are situations when the President, Vice President, Speaker of the House, President pro tempore of the Senate, and members of the Cabinet all might be gathered together, these situations could potentially present a huge security vulnerability, and the designated survivor concept is designed to reduce that vulnerability.

The identity of the designated survivor is often kept concealed until the last minute, and the location where the designated survivor shelters is always kept confidential. Along with a designated survivor to take over the Presidency, the government also usually shelters a high-ranking Senator who could take over as President pro tempore, along with a Congressperson who can step in as the Speaker of the House.

A catastrophic event which has required the services of the designated survivors has yet to appear, and the American government fervently hopes it never does. A number of political and legal issues could arise in the event that most of the Presidential line of succession was wiped out, especially if Congress was impacted as well. For example, while appointing a designated survivor to take over as the Speaker of the House might sound logical, the Speaker is an elected official, and technically the House would need to be able to form a quorum to elect the designed survivor for him or her to be legally supported. Likewise with the President pro tempore of the Senate, who is also an elected member of government.

Members of the Presidential line of succession generally take turns acting as the designated survivor. Because non-natural citizens and acting officials who are standing in as temporary replacements cannot legally assume the Presidency, they are not asked to serve as designated survivors.