Gov. John Lynch was surrounded by cheering supporters of the move as he signed the three bills about an hour after the key vote on the legislation in the House.
The law will take effect in January, exactly two years after the state legalized civil unions. New Hampshire joins Massachusetts, Connecticut, Maine, Vermont and Iowa in recognizing same-sex marriages, though opponents hope to overturn Maine’s law with a public vote.
Lynch demanded — and got — language protecting the rights of religious opponents of gay marriage before signing the bills.