A Presidential Alert is a special class of alert that is issued by the President of the United States or the Administrator of the Federal Emergency Management Agency (FEMA) during a national emergency. It is one of three types of alerts that can be issued through the Wireless Emergency Alerts (WEA) system, which is used to warn the public of an impending natural or human-made disaster. The Presidential Alert is designed to let the White House inform the entire country almost instantly of grave public emergencies, such as a terrorist attack or an invasion.

It is important to note that Americans cannot opt out of Presidential Alerts, although they can choose not to receive weather and AMBER alerts. The Presidential Alert is backed by the Federal Emergency Management Agency, in coordination with the Federal Communications Commission. The Communications Act of 1934 gives the president the authority to use certain private-sector communications systems for priority messages, and the president has sole responsibility for determining when the national-level alerts can be activated.

The first nationwide test of the Wireless Emergency Alerts system and Emergency Alert System (radio and television) was conducted in 2018. During the test, FEMA sent a test National Alert to all cellular devices, and phones within range of a cell tower received a message that stated: "THIS IS A TEST of the National Wireless Emergency Alert System. No action is needed". The test was conducted to ensure that the systems continue to be effective means of warning the public about emergencies, particularly those on the national level.