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 104th United States Congress was a meeting of the legislative branch of the United States federal government, composed of the United States Senate and the United States House of Representatives. It met in Washington, D.C. from January 3, 1995, to January 3, 1997, during the third and fourth years of Bill Clinton's presidency. Apportionment of seats in the House of Representatives was based on the 1990 United States census.