MOST of the protesters were anti-racism groups and French unions protesting against surging nationalist far-right party from gaining majority in the upcoming parliament elections.
A brand-new left-wing coalition also joined the nationwide rally.
An estimated 250,000 people joined the protest, with 75,000 of them in Paris alone, according to the French Interior Ministry.
About 21,000 armed police officers were deployed to contain potential chaos.
Meanwhile, the CGT national trade union claimed as many as 640,000 people showed up at the 182 rallies held across the country.
Protesters fear the upcoming elections could be a breeding ground in electing a new generation of far-right rulers not seen since World War II.
Protesters took a united stance after the far-right party RN (Rassemblement National) came out on top of the European elections in France on Sunday, June 9.
Formerly known as the Front National, the far-right party was founded in 1972 by a neo-fascist group while its founder has been repeatedly convicted of racism and antisemitism.
