What is the highest court in the United States that interprets laws and reviews their constitutionality?

The highest court in the United States is the Supreme Court, which serves the essential function of interpreting laws and adjudicating their constitutionality. Established under Article III of the U.S. Constitution, the Supreme Court has the authority to review decisions made by lower courts and evaluate whether laws align with constitutional principles.

Significantly, the Supreme Court's rulings set precedents that guide the interpretation of laws across the nation, thereby shaping legal standards and protecting civil rights. Its role in judicial review—established in the landmark case Marbury v. Madison—allows it to invalidate federal and state laws that do not conform to the Constitution. This judicial power underscores the concept of checks and balances within the government, ensuring that no legislative or executive action can override constitutional rights.

In contrast, the other courts listed, such as Circuit Courts, District Courts, and Appellate Courts, function at lower levels within the judicial hierarchy. These courts handle various cases and appeals but do not possess the overarching authority to interpret constitutional issues or establish binding nationwide precedents. Hence, the Supreme Court stands out as the ultimate arbiter of the law within the U.S. judicial system.