The high court acted in a one-line order without further comment.
Lawyers for a group seeking to intervene in the case had asked Justice Anthony Kennedy to postpone the judge’s ruling to allow more time for an appeal.
The group, the National Organization for Marriage (NOM), supports retaining the traditional definition of marriage of a union between one man and one woman.
Justice Kennedy requested briefs from Oregon officials and the same-sex couples who had filed the initial lawsuits. Oregon officials had ceased to defend the ban in the case before the federal court, calling the measure unconstitutional, and both the state and the couples urged the Supreme Court to reject the stay request.
“The application for stay presented to Justice Kennedy and by him referred to the Court is denied,” the order said in its entirety.
The action means that same-sex couples in Oregon can continue to apply for licenses, get married, and enjoy the full benefits of marriage in that state.
On May 19, US District Judge Michael McShane struck down a 2004 amendment to Oregon’s constitution that restricted marriage to one man and one woman.
He ruled that the measure violated the Equal Protection Clause of the 14th Amendment by degrading and demeaning the relationships of committed same-sex couples by refusing to allow them to marry.
The judge ordered state officials to immediately allow same-sex couples to wed.
Hundreds of gay and lesbian couples have responded to the ruling by obtaining the once-forbidden licenses and conducting weddings.
“We are delighted that the Court has rejected NOM’s attempt to derail marriage equality in Oregon,” David Fidanque, executive director of the American Civil Liberties Union of Oregon, said in a statement.
“We are confident that marriage equality in Oregon will help pave the way for marriage equality nationwide,” he said.
The action marked the latest turn in what has been a whirlwind federal court case challenging the constitutionality of a 2004 state-wide referendum.
The state’s attorney general, Ellen Rosenblum, announced midway through the litigation that she had decided that the marriage restriction was unconstitutional and that her office would no longer defend the measure. She also announced that her office would not comply with a state provision that barred recognition of same-sex marriages performed in other jurisdictions.
The action meant that the defendants in the case – the State of Oregon – would no longer oppose the arguments of the same-sex couples who were suing the state to be allowed to marry.
Judge McShane conducted a hearing and agreed with both the couples and the attorney general that the ban on same-sex marriages was unconstitutional.
Lawyers with NOM sought to intervene in the case, arguing that no one in the proceeding was properly representing the interests of the Oregon voters who supported the state-wide referendum restricting marriage.
Judge McShane denied NOM’s motion to intervene. The same motion is now pending at the appeals court, which also declined to issue a stay.
The NOM lawyers were asking the Supreme Court to halt Judge McShane’s order – and halt ongoing marriages – while the group sought authority to intervene.
In a statement, NOM Chairman John Eastman said he was disappointed by the Supreme Court’s action. He said the group would maintain its appeal at the Ninth US Circuit Court of Appeals.
“We will continue to press this case because we believe that the people of Oregon are entitled to a vigorous defense of marriage, and because it is in the public interest to preserve marriage as a union of one man and one woman,” Mr. Eastman said.
In recent months, eight federal judges have struck down state bans on same-sex marriage. Stays have been issued in six of the eight cases.
The two cases where stays were not issued are Oregon and Pennsylvania. In both cases, the state attorney general had concluded that the marriage bans were unconstitutional. And in both cases state officials refused to file an appeal, thus ending the litigation.
In contrast, the six other cases involve lawsuits and decisions that are being contested and appealed by state officials. Those states are Utah, Oklahoma, Virginia, Texas, Michigan, and Idaho.
With the recent decisions in Oregon and Pennsylvania, same-sex marriages are now legal in 19 states and the District of Columbia.