The Establishment Clause is a limitation placed upon the United States Congress preventing it from passing legislation forcing an establishment of religion, broadly making it illegal for the government to promote theocracy or promote a specific religion with taxes.

establishment clause, also called establishment-of-religion clause, clause in the First Amendment to the U.S. Constitution forbidding Congress from establishing a state religion. It prevents the passage of any law that gives preference to or forces belief in any one religion.

The Establishment Clause is found in the First Amendment to the U.S. Constitution. This cause prohibits the federal government from making any law regarding the establishment of, or freedom to practice religion. In simple terms, the Establishment Clause prohibits the United States government from establishing an official religion, as well as from taking any actions that favor one religion over another.