Its report, called Deeper Luxury, ranked major fashion brands on their ethical and environmental performance. None of the companies scrutinised scored more than a C+ for their efforts.
The highest scoring company was L'Oreal, which achieved a C+ for its performance across WWF's own sustainability criteria, as well as the brand's performance in the media and its relationship with NGOs.
L'Oreal was joined by Hermes and LVMH in achieving a C+ grade, while Coach closely followed with a C.
Tiffany & Co, Swatch, PPR and Richemont scored Ds, while WWF gave F grades to Bulgari and Tod's.
WWF said its report found that luxury brands had to do more to "justify their value" in a resource-constrained society. There must also be more onus on major brands to act responsibly and ethically with their practices.
WWF said global fashion and cosmetic brands had been slow in embracing their responsibilities in a resource-stricken world.
Anthony Kleanthous, senior policy advisor at WWF, said: "Luxury companies must do more to justify their value in an increasingly resource-constrained and unequal world.
"Despite strong commercial drivers for greater sustainability, luxury brands have been slow to recognise their responsibilities and opportunities."
The report also critiqued the use of celebrity endorsements for brands, saying that sports stars and actors who accepted millions of dollars to front fashion campaigns "have a responsibility" to ensure they are putting their name to brands that do not damage the environment.
Kleanthous said: "The world of celebrity leads by example and generates an aspirational desire for branded products. These stars have the responsibility to make sure that the brands they are endorsing are not damaging the planet.
"Let's face it, who wants to pay extra for a dirty brand?"
The full WWF report can be read .