Same-sex marriage has been legally recognized in Oregon since May 19, 2014, when a U.S. federal district court judge ruled that Oregon's 2004 state constitutional amendment banning such marriages discriminated on the basis of sexual orientation in violation of the Equal Protection Clause of the federal constitution. A campaign that was then under way to win voter approval of a constitutional amendment legalizing same-sex marriage was suspended following the decision. In July 2015, the Governor of Oregon signed into law a bill passed by the state legislature to codify gender-neutral marriage in various Oregon statutes. The law change went into effect on January 1, 2016.
Oregon began recognizing same-sex marriages from other jurisdictions in October 2013. Domestic partnerships have been allowed since 2008.
In March and April 2004, Multnomah County issued marriages licenses to more than 3,000 same-sex couples until ordered by a state judge to stop doing so. In November, Oregon voters approved an amendment to the state constitution that made it state policy to recognize only marriages "between one man and one woman". The validity of the licenses issued the previous spring was disputed, and the Oregon Supreme Court ruled in April 2005 that the newly adopted constitutional amendment had invalidated them.
On March 3, 2004, Multnomah County began issuing licenses to same-sex couples after its attorney issued a legal opinion that such marriages are lawful. On that day, Multnomah County issued 422 marriage licenses, compared to the 68 it issues on an average day. Local businesses reported an increase in the sales of flowers and other marriage-related services directly related to the beginning of same-sex marriages. According to the 2000 US Census, 3,242 same-sex couples were living in the county. Neighboring Washington and Clackamas Counties announced that they were studying Multnomah County's legal opinion, but did not plan to immediately follow suit.