Federal law is the body of law created by the federal government of a nation. Examples of federal governments include Australia, the United States of America, Canada, the former Union of Soviet Socialist Republics, India, Germany. The European Union is evolving into a Federal system.

The United States Constitution provides for a federal government that is superior to state governments with regard to its enumerated powers . These powers include the authority to govern international affairs, the currency, and national defense. After the Civil War, the Fourteenth Amendment applied the Bill of Rights to state governments. Issues that arise under any legislation passed by Congress, an Executive Order of the President or a decision of federal courts persuant to the United States Constitution are governed by federal law.

The Supreme Court of the United States has the sole authority to interpret the Constitution and makes final decisions regarding all federal laws. Congress has created inferior courts.