Anti-miscegenation laws or miscegenation laws were laws that enforced racial segregation at the level of marriage and intimate relationships by criminalizing interracial marriage and sometimes also sex between members of different races. Such laws were first introduced in North America from the late seventeenth century onwards by several of the Thirteen Colonies, and subsequently by many US states and US territories and remained in force in many US states until 1967. After the Second World War, an increasing number of states repealed their anti-miscegenation laws. In 1967, in Loving v. Virginia, the remaining anti-miscegenation laws were held to be unconstitutional by the Supreme Court of the United States. Similar laws were also enforced in Nazi Germany as part of the Nuremberg laws, and in South Africa as part of the system of Apartheid. In the United States, interracial marriage, cohabitation and sex have been termed "miscegenation" since the term was coined in 1863. Contemporary usage of the term is less frequent, except to refer to historical laws banning the practice.
In the United States, there have been no nationwide anti-miscegenation laws. However, there were state laws in individual states, particularly in the Southern States and the Plains States, that prohibited miscegenation. These laws were a part of American law since before the United States was established and remained so until ruled unconstitutional in 1967 by the U.S. Supreme Court in Loving v. Virginia. Typically defining miscegenation as a felony, these laws prohibited the solemnization of weddings between persons of different races and prohibited the officiating of such ceremonies. Sometimes, the individuals attempting to marry would not be held guilty of miscegenation itself, but felony charges of adultery or fornication would be brought against them instead. All anti-miscegenation laws banned the marriage of whites and non-white groups, primarily blacks, but often also Native Americans and Asians. In addition, the state of Oklahoma in 1908 banned marriage "between a person of African descent" and "any person not of African descent"; Louisiana in 1920 banned marriage between Native Americans and African Americans (and from 1920–1942, concubinage as well); and Maryland in 1935 banned marriages between blacks and Filipinos. In many states, anti-miscegenation laws also criminalized cohabitation and sex between whites and non-whites.