The U.S. Supreme Court rules, 5–4, that Section 3 of the Defense of Marriage Act is unconstitutional and in violation of the Fifth Amendment to the United States Constitution.

The Supreme Court of the United States (SCOTUS) is the highest court in the federal judiciary of the United States. It has ultimate appellate jurisdiction over all U.S. federal court cases, and over state court cases that turn on questions of U.S. constitutional or federal law. It also has original jurisdiction over a narrow range of cases, specifically "all Cases affecting Ambassadors, other public Ministers and Consuls, and those in which a State shall be Party." In 1803, the court asserted itself the power of judicial review, the ability to invalidate a statute for violating a provision of the Constitution via the landmark case Marbury v. Madison. It is also able to strike down presidential directives for violating either the Constitution or statutory law.

United States v. Windsor, 570 U.S. 744 (2013), is a landmark United States Supreme Court civil rights case concerning same-sex marriage. The Court held that Section 3 of the Defense of Marriage Act (DOMA), which denied federal recognition of same-sex marriages, was a violation of the Due Process Clause of the Fifth Amendment.

The Defense of Marriage Act (DOMA) was a United States federal law passed by the 104th United States Congress and signed into law by President Bill Clinton on September 21, 1996. It banned federal recognition of same-sex marriage by limiting the definition of marriage to the union of one man and one woman, and it further allowed states to refuse to recognize same-sex marriages granted under the laws of other states.

The Fifth Amendment to the United States Constitution creates several constitutional rights, limiting governmental powers focusing on criminal procedures. It was ratified, along with nine other amendments, in 1791 as part of the Bill of Rights.