New Hampshire State Law New Hampshire recognizes same-sex relationships under state law as follows: Same-Sex Marriage Same-sex marriage is legal in New Hampshire.  Marriages legally contracted in other jurisdictions, which would not be prohibited in New Hampshire, are generally recognized as valid. Civil unions legally contracted in other jurisdictions are also generally recognized as marriages in New Hampshire.  Click here for more information. Civil Unions Effective January 1, 2011, existing civil unions in New Hampshire merged into marriages by operation of law. Civil unions legally contracted in other jurisdictions are generally recognized as marriages in New Hampshire.  Click here for more information.