Same-sex marriage in New Hampshire

Same-sex marriage has been legal in New Hampshire since January 1, 2010, based on legislation signed into law by Governor John Lynch on June 3, 2009. Following much discussion, a same-sex marriage bill was approved 14–10 by the Senate and 198–176 by the House of Representatives in May 2009. The law provided that civil unions, which the state had established on January 1, 2008, would be converted to marriages on January 1, 2011, unless dissolved, annulled, or converted before that date. Efforts to repeal the law were defeated in the House in March 2012. Polling suggests that a large majority of New Hampshire residents support the legal recognition of same-sex marriage, with a 2024 Public Religion Research Institute poll showing that 74% of respondents supported same-sex marriage.

New Hampshire was the fourth state in New England and the fifth in the country, after Massachusetts, Connecticut, Iowa and Vermont, to legalize same-sex marriage.