Carrying a sign reading "overconsumption = extinction," the woman representing Amis de la Terre France, Youth for Climate and Extinction Rebellion marched down the same path as the models, causing a stir in the audience, a Reuters witness said.
In the front row, French cinema stars Catherine Deneuve and Isabelle Huppert hardly flinched, while some members of the Arnault clan, seated next to LVMH chief executive officer and chairman Bernard Arnault, glanced at each other.
The protester was wrestled to the ground by security before being led away.
The disruption hardly interrupted the flow of models who charged down the cobblestoned runway in a corridor of the Louvre to dramatic organ music punctuated with bell tolls.
The show itself had a punk flavor, with sleeves ripped off suit jackets, leaving arms bare, and accessories including studded boots and chainmail headpieces.
Amis de la Terre France said it targeted the LVMH-owned label to throw a spotlight on the issue of overconsumption.
"LVMH is the world leader of luxury and has a responsibility when it comes to trends that push the textile industry to constantly renew collection faster and produce more," Alma Dufour, a group spokesperson, told Reuters.