The Senate voted 19-6 for the bill Friday, sending it to the state House of Representatives for additional consideration.
Hawaii would become the sixth state to grant some of the rights of marriage to same-sex couples without authorizing marriage itself. A civil unions bill also passed the Illinois Legislature last month.
Democrats, who control the Hawaii Legislature, have said they plan to approve the bill quickly this year and send it to new Democratic Gov. Neil Abercrombie for his signature. Abercrombie has said he supports civil unions.
A similar bill was vetoed last year by then-Gov. Linda Lingle, a Republican.
One more step on the road to equality! It is a great day in Hawaii!!