- Civil marriage equality in effect at the district level since 2010. (Same-sex couples may legally marry.)
- Since 1992, the District has allowed residents to enter into registered domestic partnerships; since the passage of the Domestic Partnership Judicial Determination of Parentage Act of 2009, the District recognizes civil unions and domestic partnerships performed in other jurisdictions that have all the rights and responsibilities of marriage. The law gives the mayor discretion to recognize relationships from states with lesser benefits.
- 8 December 2009, marriage equality was legalized in the District of Columbia when District Mayor Adrian Fenty signed a bill passed by the Council 3 days previously. Following the signing, the measure entered a mandatory Congressional review of 30 work days. Marriage licenses became available on 3 March 2010, and same-sex marriages began on 9 March 2010.
- The District was the first jurisdiction in the United States below the Mason–Dixon Line to allow same-sex couples to marry.