How did Mexico City’s same-sex marriage law affect recognition of marriages across Mexico?

In 2009, the Federal District of Mexico City became the first jurisdiction in Mexico to legalize same-sex marriage. Following this legislative change, the Supreme Court of Mexico issued a ruling in 2010 declaring that same-sex marriages performed in Mexico City were constitutional and must be recognized throughout the country.12

This decision established a critical precedent for the legal recognition of such unions across all Mexican states, even in jurisdictions that had not yet legalized same-sex marriage themselves. While same-sex marriage was not immediately legalized nationwide, this ruling ensured that couples married in Mexico City held valid marital status across the entire nation. Subsequently, other jurisdictions began to legalize same-sex marriage, and in 2015, the Supreme Court issued further rulings that made it easier for couples to marry and provided the right to seek court injunctions against state-level bans.132