[[File:World marriage-equality laws.svg|thumb|right|upright=2.0| {{legend|#002255|Marriage open to same-sex couples}} {{legend|#71C837|Legislation or binding domestic court ruling establishing same-sex marriage, but marriage is not yet provided for}} {{legend|#9900CC|Same-sex marriage recognized when performed in certain other jurisdictions, and accorded greater rights than local same-sex unions (if any)}} {{legend|#0066FF|Civil unions or domestic partnerships}} {{legend|#9FCFFF|Limited legal recognition}} {{legend|#CCAAFF|Limited recognition of marriage performed in certain other jurisdictions (residency rights for spouses)}} {{legend|#C6E9AF|Country subject to an international court ruling to recognize same-sex marriage}} {{legend|#CCCCCC|Same-sex unions not legally recognized}}]] Same-sex marriage is legal in the following countries: Andorra, Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, Colombia, Costa Rica, Cuba, Denmark, Ecuador, Estonia, Finland, France, Germany, Greece, Iceland, Ireland, Luxembourg, Malta, Mexico, the Netherlands, New Zealand, Norway, Portugal, Slovenia, South Africa, Spain, Sweden, Switzerland, Taiwan, the United Kingdom, the United States, and Uruguay. Same-sex marriage is recognized, but not performed, in Israel and Namibia. Furthermore, same-sex marriages performed elsewhere in the Kingdom of the Netherlands are recognized in Sint Maarten. Whether same-sex couples should be allowed to marry has been and remains the topic of debate worldwide. 32 countries and four jurisdictions worldwide have passed constitutional amendments that explicitly prohibit the legal recognition of same-sex marriage and sometimes other forms of legal unions as well. Sixteen countries and 34 jurisdictions worldwide have authorized civil unions or unregistered cohabitation for same-sex couples as an alternative to marriage. The legal name of those unions as well as the number of rights that they provide can vary greatly.

Legislative efforts to recognise same-sex unions

National level

The first legislation of unregistered cohabitation was introduced in the Netherlands in June 1979. However, the first substantial recognition of same-sex couples did not occur before the introduction of a new legal form, that of registered partnerships, which was first enacted in Denmark in June 1989. Many countries have followed with similar legislation since then. Legislation of these forms of legal unions still occur with a variety of different names, even after the introduction of same sex marriage, although sometimes they are overwritten by subsequent legislation of same-sex marriage. As of, certain alternative form of legal recognition other than marriage has been allowed on a national level in Bolivia, Croatia, Cyprus, Czechia, Hungary, Italy, Latvia, Liechtenstein, Monaco, Montenegro, and San Marino. As of, legislation to allow an alternative form of legal recognition of same-sex couples other than marriage is pending, or has passed at least one legislative house on a national level in Kosovo and Poland. As of, same-sex marriage has been legal (nationwide or in some parts) in Andorra, Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, Colombia, Costa Rica, Cuba, Denmark, Ecuador, Estonia, Finland, France, Germany, Greece, Iceland, Ireland, Luxembourg, Malta, Mexico, the Netherlands, New Zealand, Norway, Portugal, Slovenia, South Africa, Spain, Sweden, Switzerland, Taiwan, the United Kingdom, the United States, and Uruguay. As of, legislation to allow same-sex marriage is being considered in at least one legislative house on a national level in Italy and Japan. Notes:

Sub-national level

In countries with a federal system of governance, states and territories often may grant recognition to same-sex couples in their own jurisdictions, although unitary states with a level of devolution, such as Spain or the United Kingdom, also offer such powers to local authorities. The first jurisdiction to enact unregistered cohabitation was British Columbia in Canada in July 1992. The first jurisdiction to legalize registered partnership was Greenland as part of the Kingdom of Denmark in April 1996. Finally, the first sub-national jurisdiction to legalize same-sex marriage was the Canadian province of Ontario in June 2003. As of, there are 32 sub-national jurisdictions worldwide that have legalized some kind of alternative form of legal union of same-sex couples other than marriage. Those are: For the time being, 63 sub-national jurisdictions worldwide have legalized same-sex marriage in nations where same-sex marriage is not legal throughout the nation's territory. Those are: Note:

Prohibition of same-sex unions

Legislative efforts

Various countries have passed (or tried to pass) legislation to prevent same-sex marriage or repeal the existing laws (in some cases including criminalization or fines). Sometimes approving explicit bans or defining marriage as solely the union between a man and a woman, excluding all others.

National level

Notes:

Constitutional efforts

Thirty-two countries have passed constitutional amendments banning a variety of same-sex unions. These amendments have taken several forms. Some are limited to banning only marriage. Others ban marriage and prohibit legislation providing "similar rights".

National level

Cuba was the first country to prohibit same-sex marriage in February 1976. Paraguay, Honduras and Bolivia are the only cases that not only marriage is prohibited but also de facto unions. Vietnam, Cuba, and Ecuador repealed their same-sex marriage bans in November 2013, April 2019, and June 2019, respectively. As of, thirty-three countries prohibit same-sex marriage on a national level. Those are Armenia, Belarus, Bolivia, Bulgaria, Burkina Faso, Burundi, Cambodia, the Central African Republic, Croatia, the Democratic Republic of the Congo, Dominican Republic, Georgia, Honduras, Hungary, Jamaica, Kenya, Kyrgyzstan, Latvia, Lithuania, Mali, Moldova, Mongolia, Montenegro, Palau, Paraguay, Poland, Russia, Rwanda, Serbia, Slovakia, South Sudan, Uganda, Ukraine, Venezuela and Zimbabwe. Notes:

Sub-national level

The first jurisdiction to explicitly ban same-sex marriage in its Constitution was the U.S. state of Alaska in November 1998, however, same-sex marriage was legalised in the state in October 2014. The first jurisdiction to enact such a ban was Yucatán, in July 2009, but since August 2010 the state recognizes same-sex marriages performed in Mexico and in August 2021 local congress removed the heterosexual definition of marriage from the state's constitution. Notes: