"The vote on this article marks a victory in the fight against homophobia and for tolerance and democracy," said Francois Rebsamen, head of the Socialist group in the Senate, said in a statement after the vote Tuesday.
Despite efforts by Senate opponents of same-sex marriage, the measure was passed without amendments and on the first vote, meaning it won't have to be returned to the lower chamber for consideration, France's version of The Local reported Wednesday.
While the vote does not formally write same-sex marriage into French law, the Senate would have to reject the entire bill to prevent it from becoming law, officials said.
"The adoption of this article by a united Senate majority, puts an end to discrimination resulting from the sexual choices of our citizens," Rebsamen said.
The Senate is expected to vote on the entire bill in several weeks.
France's highest court, the Constitutional Council, which has the power to reject legislation if it is contrary to the country's constitution, already said it would accept what lawmakers decide, The Local.fr reported.
France would become the 12th country to legalize same-sex marriage if lawmakers approve the bill.