Hawaii's governor has signed into law a bill extending marriage rights to same-sex couples in the state.
Hawaii has long been popular as a wedding and honeymoon destination and regarded as a pioneer in advancing the cause of gay matrimony.
With the signing by Governor Neil Abercrombie, Hawaii became the fifteenth US state to legalize marriage for gay and lesbian couples.
The measure, which takes effect on 2 December, gained final approval from the Democrat-controlled state legislature yesterday, 15 days after the start of a special session called by Mr Abercrombie.
Illinois' General Assembly beat Hawaii to the punch by a week, giving final approval to a same-sex marriage bill on 5 November.
However, Illinois Governor Pat Quinn is not expected to sign that measure until later this month.
The new Hawaii law rolls back a 1994 statute defining marriage as a union between a man and a woman.
Moments before signing, Mr Abercrombie spoke about how, despite misgivings by opponents who felt their religious beliefs were infringed, the measure served the "greater good" by more fully embracing gay and lesbian members of society, who had long felt marginalised.
The path to legal gay marriage in Hawaii has been long and bumpy.
The state's Supreme Court ruled 20 years ago that barring same-sex nuptials was discriminatory, in a landmark opinion that advanced the cause of gay marriage nationwide but sparked a backlash that has until now kept matrimony limited toh eterosexual couples in Hawaii.
Amended in the state House of Representatives last week to strengthen exemptions for clergy and religious groups, the measure cleared the Senate, 19-4, yesterday, with the body's lone Republican joining three Democrats in opposing it.
Two other Democrats were absent.
The House had passed the bill, 30-19, with the support of just one of that chamber's seven Republicans. Thirteen Democrats voted against it.
The move to lift Hawaii's ban on same-sex marriage comes a ta time of growing momentum for gay rights in the courts, at the ballot box and in statehouses across the United States.
The trend has gained steam since the US Supreme Court ruled in June that married same-sex couples are eligible for federal benefits, striking down a key part of the 1996 federal Defense of Marriage Act.