Born Manfred Thierry Mugler, the Strasbourg-bred designer began crafting clothing in 1970s but it wasn't until the '80s and '90s that he became an internationally recognized designer, creating clothing for Demi Moore in films like Indecent Proposal and on the red carpet for Sharon Stone, David Bowie, George Michael and more, with Tyra Banks and Cindy Crawford among the top models of the time to wear his looks on the runway.
Mugler left fashion in 2003, but still collaborated with celebs and even launched his own beauty line that has since released a host of fragrances, including Angel and Alien.
In recent years, stars like Kim Kardashian, Cardi B, Beyoncé, Robin Wright, Nicole Kidman, Lady Gaga, Megan Fox and Miley Cyrus have all rocked his ensembles.
Though he officially retired from fashion in the early aughts, Mugler made an exception to design under "House of Mugler" for the 2019 Met Gala, creating the wet couture dress Kardashian famously wore to the gala that year.
Mugler's death comes less than a week after the fashion world mourned the loss of another icon in the industry, André Leon Talley.
No other details surrounding Mugler's sudden death have been revealed, but ET has reached out to his reps for comment.