The accident happened late Sunday night at a festival in the small village of Saint-Maurice-de-Cazevieille, around 70 kilometres (50 miles) to the north of the city of Montpellier.
According to witnesses cited in local media, the man was standing outside the safety barriers along the bull run route when he was hit.
The bull is released in an enclosed square, goaded by youths who try to avoid the animal's charges, cheered on by locals standing behind barriers.
Better known in Spain, bull running is also popular in southern French villages.
Although the controversial spectacle, known as La Corrida in France, is fairly alive and well in certain parts of the south west, those who want to see it banned in France scored a symbolic blow earlier this month.
Corrida was added to the French Ministry of Culture’s list of “intangible heritage” to much controversy back in 2011, before they removed any mention of it from their website amid a huge hullaballoo.
Animal rights campaigners wanted it withdrawn completely but an appeal court ruled that in the minds of judges it was already done and considered that bullfighting had been annulled from the heritage list.
Roger Lahaha, vice president of the animal rights group CRAC Europe described the decision as “an immense victory”.
“It is one more step towards the abolition of a barbarism that belongs to another age,” he told France's Huffington Post.