A police official said two people were arrested but there were no reports of injuries, Britain's Guardian reported.
Authorities estimated hundreds of thousands of people joined the protest Sunday.
The protesters gathered near the Arc de Triomphe and Champs-Elysees calling on French President Francois Hollande and the Senate to drop the bill after it was easily approved in the lower house of Parliament, Euronews.com reported.
The "marriage for everyone" bill was expected to pass the Senate, though protests have weakened support for it, observers said.
Some conservative activists pushed through police lines during the protest, Euronews.com reported. Police responded by firing tear gas.
Protesters at the Arc de Triomphe called on Hollande to drop the same-sex marriage bill and focus instead on the country's flagging economy, The New York Times reported.
A banner on a balcony in the area read, "We want work not gay marriage."
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