The World Factbook (also known as the CIA World Factbook) is an annual publication of the Central Intelligence Agency of the United States with almanac-style information about the countries of the world. The Factbook provides a two- to three-page summary of the demographics, geography, communications, government, economy, and military of 266 U.S.-recognized countries, dependencies, and other areas in the world.

The World Factbook is prepared by the CIA for the use of U.S. government officials, and its style, format, coverage and content are primarily designed to meet their requirements. However, it is frequently used as a resource for student papers, web sites and non-governmental publications. As a work of the U.S. government, it is in the public domain.