Hawaii's Governor Neil Abercrombie has signed the civil union bill into law, making Hawaii the seventh U.S. state to grant the measure to same-sex couples without authorising marriage itself.
A majority of lawmakers in Hawaii supported the passage of the bill through the state's House and Senate.
Governor Abercrombie said this bill has been an emotional process that's now ended.
At the signing, he said this bill represented equal rights for everyone in Hawaii, which he says is part of the aloha spirit.
"To have the opportunity, at this stage of my public career to be able to advance to me, the essence of aloha, is something that I truly treasure and honour with my signature. Senate bill Number 232, Senate draft 1, House draft number 1, is now law."
Hawaii's civil union measure takes effect at the beginning of January.