In international relations theory, the term "new world order" refers to a new period of history evidencing a dramatic change in world political thought and the balance of power. However, in conspiracy theory, the term "New World Order" (the capital letters are distinguishing) refers to the advent of a cryptocratic or totalitarian world government.

The common theme in conspiracy theories about a New World Order is that a powerful and secretive group of globalists is conspiring to eventually rule the world through an autonomous world government, which would replace sovereign states and other checks and balances in international power struggles. Significant occurrences in politics and business are speculated to be caused by an extremely influential cabal operating through many front organizations. Numerous historical and current events are seen as steps in an on-going plot to achieve world domination primarily through secret political gatherings and decision-making processes.

Social critics, such as political scientist Michael Barkun, have expressed concern that the synthesis of paranoid theories about a New World Order conspiracy, which were once limited to American far-right audiences, has given them mass appeal and enabled them to become commonplace in mass media, thereby inaugurating an unrivaled period of millenarian activity in the United States of the late 20th and early 21st century. Some warn that this development may have devastating effects on American political life, such as producerist demagogy influencing elections as well as domestic and foreign policy