Same-sex marriage has been legal in the Mexican state of Michoacán since 23 June 2016. On 18 May 2016, the state Congress approved a bill to legalise same-sex marriage in the state by a vote of 27 in favour, none opposed and 8 abstentions. Previously, Congress had refused to amend the Civil Code to legalize same-sex marriage, despite a ruling by a state judge requiring it to do so.Michoacán also offers civil unions to same-sex and opposite-sex couples.
On 13 November 2006, it was announced that civil unions bills would be formally proposed. However, the bills stalled in the local Congress. After same-sex marriage was passed in the Federal District, the Party of the Democratic Revolution (PRD) announced it would propose bills for same-sex marriage and adoption, along with a "Law for Coexistence Partnerships" to allow same-sex civil unions in 2010. A bill was submitted in March 2010 by the Grupo de Facto Diversidad Sexual, which proposed both marriage and cohabitation, but did not mention same-sex adoption. As with the previous proposals, it stalled.
On 27 August 2015, the Justice and Human Rights Committee approved a new text of the Family Code that maintained the heterosexual definition of marriage but enacted domestic partnerships (Spanish: sociedad de convivencia) for same-sex couples. It was approved unanimously by the full Michoacán Congress on 7 September 2015. The law was published on 30 September 2015 in the state's official journal. Following the Family Code's passage, a lawsuit claiming discrimination and unconstitutionality was filed before the Mexican Supreme Court in October.
Since 23 June 2016, a domestic partnership is defined as the legal union between two individuals. Such unions are therefore open to both opposite-sex and same-sex couples (they were previously open to same-sex couples only).
After 4 years of legal processes, on 5 March 2014, a federal court ruled that a lesbian couple could marry. It was the first case in Mexico which was not elevated to the Supreme Court. The couple married on 12 March 2014. On 6 May 2014, it was announced that a second lesbian couple had obtained an injunction and seven more cases were pending. They married on 16 May 2014 and, subsequently on 15 August 2014, filed the registration of their twin children's birth, which had also been approved by an injunction. It was the first registration in the state of a child born to a same-sex couple. Gerardo Herrera Pérez, leader of Grupo de Facto Diversidad Sexual en Michoacán, announced that they had collected 100 signatures for a collective amparo (injunction) in Michoacán in September 2014 and the initiation of the first same-sex adoption in the state by a couple, who married in Mexico City.
On 20 June 2015, it was announced that a lesbian couple had gained an amparo in Michoacán, making them the third couple to obtain an amparo in the state. It was noted that their initial application for an injunction was made one month prior. On 29 June 2015, the Civil Registry announced that they had formalized six same-sex unions in the previous year, but the laws of the state had not changed and it might take an injunction to force the issue. On 10 July 2015, a 7th district judge ordered the state to accommodate a lesbian couple's injunction. The ruling gave the Governor and the Congress President until 15 July 2015 to make the arrangements and revise the laws mentioning marriage, or face penalties for the previous approval of the Family Code which excluded same-sex couples that was later deemed unconstitutional. The attorney leading the injunction told the media that state leaders would be found liable for not vetoing the discriminatory revision of the Family Code if it was not modified in accordance with the judge's order. It was announced on 13 July 2015 that Congress would abide by the judge's ruling. When questioned by the media on 14 July 2015, Governor Salvador Jara Guerrero declared that the changes would be applied on 15 July and was quoted as saying "Of course!" to removing the heterosexual definition of marriage in the state's code. On 31 July 2015, it was announced that an additional 19 new amparos permitting same-sex marriage had been granted in Michoacán. In making the announcement, deputies Talía Vázquez Alatorre and Cristina Portillo Ayala regretted that the Congress still had yet to act, but hoped that these further injunctions would emphasize the need for passage of the reforms to the Civil Code.
On 18 May 2016, the state Congress approved a same-sex marriage bill by 27 votes to 0, with 8 abstentions. This had followed previous attempts to pass a domestic partnerships law for same-sex couples instead of a same-sex marriage law as required by a judicial ruling in July 2015 (see above). The marriage law was published in the state's official diary on 22 June 2016 and came into effect on 23 June. It allows same-sex couples to adopt children jointly.
From June 2016 to May 2017, 86 same-sex marriages took place in the state. Most of these marriages were celebrated in Morelia, the state's capital, followed by Uruapan, Zamora, Apatzingán, La Piedad, Lázaro Cárdenas, Pátzcuaro, Puruándiro, Zinapécurao and Zitácuaro. Additionally, the Civil Registry began training its employees to realise that same-sex marriage is indeed legal in Michoacán, as according to some reports several same-sex couples had been turned away when applying for marriage certificates. Some officials were unaware that same-sex marriage is legal in the state.
A 2017 opinion poll conducted by Gabinete de Comunicación Estratégica found that 48% of Michoacán residents supported same-sex marriage. 49% were opposed.
According to a 2018 survey by the Instituto Nacional de Estadística y Geografía (INEGI), 46% of the Michoacán public opposed same-sex marriage.