Same-sex marriage has been legally recognized in Colorado since October 7, 2014.Colorado AG: County clerks must issue gay marriage licenses Colorado's state constitutional ban on same-sex marriage was struck down in state district court on July 9, 2014, in Brinkman v. Long, and by the U.S. District Court for the District of Colorado on July 23, 2014, in Burns v. Hickenlooper. The Tenth Circuit Court of Appeals had already made similar rulings with respect to such bans in Utah on June 25 and Oklahoma on July 18, which are binding precedents on courts in Colorado. On October 6, 2014, the U.S. Supreme Court declined to hear the cases, and the Tenth Circuit lifted its stay. On October 7, the Colorado Supreme Court and the Tenth Circuit cleared the way for same-sex marriages to begin in the state.Statement of the Colorado Attorney-General - October 7, 2014 Colorado was the 25th U.S. state to legalize same-sex marriage. Polling suggests that a large majority of Colorado residents support the legal recognition of same-sex marriage.
Colorado had previously denied marriage rights to same-sex couples by statute since 2000 and in its State Constitution since 2006. In 2024, voters repealed the state's constitutional ban on same-sex marriages by 64–36 percent. Statutes were also updated to reflect the legalization of same-sex marriage in 2025. The Colorado General Assembly had also enacted a law recognizing civil unions providing some of the rights and benefits of marriage in 2013.
Civil unions
Civil unions have been legal in Colorado since May 1, 2013. Legislation to establish civil unions was passed in the Colorado Senate by 21 votes to 14 on February 11, 2013, and by the House of Representatives on March 12 in a 39–26 vote. Governor John Hickenlooper signed the bill into law on March 21, and the law took effect on May 1. Civil unions, open to both same-sex and opposite-sex couples, provide rights comparable to those enjoyed by married couples, including spousal employer benefits, presumption of paternity, adoption, next of kin rights, and inheritance, among others. However, as the federal government does not recognize civil unions, partners in a civil union cannot receive federal benefits.
Same-sex marriage Statutes In 1996, the Colorado General Assembly passed a bill banning same-sex marriage, but it was vetoed by Governor Roy Romer.Marriage veto The General Assembly passed a similar bill the following year, but Romer again vetoed the legislation.Gay marriage ban vetoed Following the 1998 gubernatorial election, Governor Bill Owens signed a bill banning same-sex marriage into law in 2000.Governor signs gay-marriage ban among flock of other bills In January 2025, a bill removing all provisions in Colorado statutes that restricted marriage to "one man and one woman", thereby removing the unenforceable ban on same-sex marriage, was introduced to the General Assembly by senators Jessie Danielson and Sonya Jaquez Lewis. It passed the Senate by 29 votes to 6 on February 5, and the House of Representatives by a vote of 45 to 14 on March 25. Governor Jared Polis signed it into law on April 7, 2025.
+February 5, 2025 vote in the Senate Political affiliation Voted for Voted against Absent (Did not vote) Democratic Party – – Republican Party – Total 6 0
+March 25, 2025 vote in the House of Representatives Political affiliation Voted for Voted against Absent (Did not vote) Democratic Party – Republican Party Total 14 6
Representative Brianna Titone justified the bill's necessity, "This legislation will implement the will of the voters and protect marriage equality in Colorado. As the Trump administration continues to blatantly attack and demonize the LGBTQ+ community, this bill upholds marriage equality in Colorado. With the passage of this bill, we're now one step closer to protecting the freedom to marry who we love." The definition of marriage in Colorado is now the following:
Constitutional amendments
On November 7, 2006, Colorado voters approved Amendment 43, a state-initiated constitutional amendment that prohibited the recognition of same-sex marriage in the Constitution of Colorado. The amendment passed by a margin of 56% to 44%.
Following the U.S. Supreme Court's decision in Dobbs v. Jackson Women's Health Organization, which overturned Roe v. Wade, in June 2022, some lawmakers announced they would push to codify same-sex marriage in state statutes and place a measure on the ballot to repeal the constitutional amendment banning same-sex marriage. Governor Jared Polis said he would sign such bills into law. In January 2023, Senator Danielson said, "The legislature has an obligation to do away with that ban to show the communities that we care about (them), that we're gonna stand up and protect them." A constitutional amendment requires a two-thirds majority in both chambers of the General Assembly. A ballot initiative to amend the Constitution of Colorado to remove verbiage limiting marriage to "one man and one woman", thereby removing the constitutional prohibition of same-sex marriage, was filed in July 2023. In April 2024, Senator Joann Ginal and representatives Alex Valdez and Brianna Titone introduced a constitutional amendment to the General Assembly to refer the issue to voters. The Senate approved the measure 29–5 on April 29, with six Republicans joining all Democrats in support. The House followed 46–14 on May 4, with one Democrat joining Republicans in voting against and two Republicans joining the remaining Democrats in support. The bill was signed by Governor Polis on May 8. In September 2024, a group of religious leaders expressed their support for the measure. As Amendment J, it was placed on the November 5, 2024 ballot, and approved by 64.3% of voters and a majority of counties. Support reached 80% in four counties: Pitkin (84%), Boulder (83%), Denver (82%), and San Miguel (82%). Opposition to the amendment was highest in Cheyenne (79%), Kiowa (78%) and Baca (78%) counties.
+April 29, 2024 vote in the Senate Political affiliation Voted for Voted against Absent (Did not vote) Democratic Party – – Republican Party Total 5 1
+May 4, 2024 vote in the House of Representatives Political affiliation Voted for Voted against Absent (Did not vote) Democratic Party Republican Party Total 14 5
Lawsuits There are five court cases dealing with same-sex marriage in Colorado. They are Brinkman v. Long, a state district court case, ruling in favor of same-sex marriage; Burns v. Hickenlooper, a U.S. district court (i.e. federal) case, ruling in favor of same-sex marriage; Kitchen v. Herbert and Bishop v. Smith, two decisions out of the Tenth Circuit Court of Appeals which affirm same-sex marriage and are binding precedent on Colorado courts, and Colorado ex rel. Suthers v. Hall, a state court case which previously allowed Boulder County to issue marriage licenses to same-sex couples.
Adams v. Howerton
In 1975, Clela Rorex, the Boulder County Clerk, became the first county clerk in the United States to issue marriage licenses to same-sex couples. She issued marriage licenses to six same-sex couples after the local district attorney interpreted Colorado's statutes, which used the phrase "any two persons", to be gender-neutral with respect to marriage. Attorney General J.D. MacFarlane issued a contrary opinion that those marriages were invalid, and the licenses were revoked. Dave McCord and Dave Zamora were the first couple to receive a marriage license in Boulder on March 26, 1975. When one of those married in Boulder, Richard Adams, tried to use his license to sponsor his husband, Australian national Anthony Sullivan, for immigration purposes, he lost his case, Adams v. Howerton, in federal court.Leagle, Inc.: Adams v. Howerton, 486 F. Supp. 1119 (C.D.Cal.1980) . Accessed July 30, 2011 In 2016, U.S. Citizenship and Immigration Services granted permanent residency status to Sullivan, based on his marriage to Adams in Boulder on April 21, 1975. In December 2024, U.S. Secretary of the Interior Deb Haaland announced that the Boulder County Courthouse had been designated a National Historic Landmark for being the first site in the United States to issue marriage licenses to same-sex couples.
Brinkman v. Long
After being denied a marriage license, a lesbian couple filed a lawsuit on October 30, 2013, in state district court. The case, Brinkman v. Long, sought to overturn the state's constitutional ban on same-sex marriage. The couple was joined by nine other same-sex couples who filed a lawsuit, McDaniel-Miccio v. Hickenlooper, also in state district court, seeking the same outcome. The suit named Governor John Hickenlooper and a city clerk responsible for licensing marriages as defendants. Attorney General John Suthers announced he would defend the state's ban. Brinkman and McDaniel-Miccio were combined for oral arguments in state district court. On July 9, 2014, District Court Judge C. Scott Crabtree ruled that Colorado's same-sex marriage ban violated the plaintiffs' guarantees of equal protection and due process under the Fourteenth Amendment to the U.S. Constitution, stating: "No state since United States v. Windsor has been able to justify its ban under even the rational basis test, much less under the strict scrutiny test." The judge stayed his ruling pending the outcome of appeals.
Judge Hartman's decision in Colorado ex rel. Suthers v. Hall provided legal cover for the Boulder County clerk to issue same-sex marriage licenses as a form of civil disobedience. After Hartman's decision was handed down, the Denver and Pueblo county clerks began issuing licenses to couples regardless of gender as well, despite Judge Crabtree's stay. When asked to enjoin the Denver County clerk from issuing licenses to same-sex couples, Judge Crabtree refused to take action. On July 14, 2014, Attorney General Suthers appealed Judge Crabtree's inaction to the Colorado Supreme Court. In a separate filing, and seeking a reversal of Judge Hartman's ruling, Suthers also asked the high court for an emergency injunction to stop all state clerks from issuing licenses. On July 18, 2014, the Colorado Supreme Court ordered clerks in Adams and Denver counties to stop issuing marriage licenses. The Supreme Court was scheduled to hear oral arguments regarding the merits of the state's same-sex marriage ban on September 30, 2014.
Burns v. Hickenlooper
Burns v. Hickenlooper was a same-sex marriage case filed on July 1, 2014, in the U.S. District Court for the District of Colorado. The plaintiffs were six same-sex couples who had been legally married in another state but whose marriage Colorado did not legally recognize or who had been refused a Colorado marriage license. The main defendants, Governor Hickenlooper and Attorney General Suthers, agreed with the plaintiffs insofar as having the court issue an injunction declaring the same-sex marriage ban unconstitutional, but they wanted a stay and swift resolution by the U.S. Supreme Court in order to avoid costly litigation.