The court did not comment in turning away a challenge from a Maryland pastor and others who were trying to let city residents vote on a measure that defines marriage as being between a man a woman.
Bishop Harry Jackson lead a lawsuit against the D.C. Board of Elections and Ethics after it refused to put that initiative on the ballot.
The board ruled that the ballot question would, in effect, authorize discrimination.
Council Member David Catania, who is openly gay and the author of the same-sex legislation, says while opponents of the measure have exhausted their judicial options, he expects they'll continue to lobby congress to intervene.
"As we go forward, it will be important for District officials to build relationships with the new subcommittee chairmen, especially in the House, and to advocate our point of view about this is...intrinsically a local District matter," Catania says.
Last year Washington began issuing marriage licenses for same-sex couples, and in 2009 it began recognizing gay marriages performed elsewhere.