A protester taking part in a road blockade has been killed by accident after a car crashed into her, France's Interior Minister Christophe Castaner said on Saturday.
The driver panicked when protesters surrounded her car and began banging on the roof, he said.
She then ploughed into the crowd in Pont-de-Beauvoisin, southeast France, hitting a woman in her 50s.
The protests are over rising fuel prices. Demonstrators have been trying to block major roads across France.
Around 120,000 people are estimated to have joined the "yellow vests" movement — named after the high-visibility jackets they wear — more than 2,000 protests.
As well as the one death, there have also been 47 people injured, including three seriously, added Castaner.
The protest prompted many posts on social media, suggesting widespread disruption to traffic across France.
The protests began at the end of last year after higher fuel taxes were introduced.
Recently they surged after petrol prices went up and now they've evolved into a wider movement against President Emmanuel Macron's government.
The yellow vests enjoy much broader support than other protests since Macron swept to power last year, with 73% of respondents backing the protests in an Elabe poll this week.
Analysts say the movement now represents more widespread frustration over stagnant spending power under Macron, a former investment banker who promised economic revival and to restore people's trust in government.
It also reflects longstanding anger among many in rural and small-town France who say the government in Paris doesn't understand the challenges facing the vast majority of the French.