The legislation now goes to the Senate for a vote in two weeks. If approved without amendments, it would then only need to be signed into law by French President François Hollande, who supports marriage reform.
French Lower House MPs approved the bill, which also allows gay couples to adopt, in February this year with 329-229 votes in favour.
Hollande’s Socialist Party majority in the Senate is expected to work in the bill’s favour on April 4.
Polls show most French people support legalising gay marriage, but there have been rallies involving hundreds of thousands of people for and against the issue in France this year.
Several days ago, Paris police banned gay marriage opponents from holding yet another protest, this time along the Champs Elysées.