In the 1970s, Mugler launched his eponymous fashion house; and quickly rose to prominence in the following decades for his avant-garde, architectural, hyperfeminine and theatrical approach to haute couture.

[1][2] He was one of the first designers to champion diversity in his runway shows, which often tackled racism and ageism, and incorporated non-traditional models such as drag queens, porn stars, and transgender women.

[5] At the beginning of his career he designed signature looks for Michael Jackson,[6] Madonna,[7] Grace Jones,[8] Duran Duran, Viktor Lazlo, David Bowie and Diana Ross; most notably Demi Moore's dress from the 1993 movie Indecent Proposal, which was once coined "the most famous dress of the 1990s".

[10][11] Mugler's fall 1995 haute couture collection, marking the 20th anniversary of his brand, was staged at the Cirque d'hiver venue in Paris; and has been referred to as the "Woodstock of Fashion", for having over 300 designed looks, an elaborate set design, dozens of high-profile supermodels and a performance from James Brown.

At 26, he began to design for a variety of large ready-to-wear fashion houses in Paris, Milan, London and Barcelona.

[27][28] In 1978, he opened his first Paris boutique at the Place des Victoires in the 1er Arrondissement and rapidly gained attention as among the most extreme of the Fall 1978 broad-shoulder brigade of designers,[29][30] with a penchant for mid-20th-century sci-fi themes[31][32][33] and exaggerated 1940s-50s-style glamour marked by sharply constructed tailoring.

He used exclusively Maud Frizon footwear in his late seventies-early eighties women's collections, the most influential shoe designer of the period.

[36][37] During the 1980s and 1990s Mugler became an internationally recognized designer, often grouped with his friends Claude Montana[38] and Azzedine Alaïa[39][40][41] but known especially for his shapely suits,[42] and his collections garnered much commercial success.

He regularly designed costumes for musical comedies, concerts, operas and the theatre (including Macbeth for the Comédie Française).

In 1990, Clarins acquired a 34 percent share in Thierry Mugler Couture when it signed a deal to produce the brand's fragrances.

[67] By 1997, Clarins increased this share to 83.5 percent, acquiring its stake by purchasing stock from Mugler, the Marceau Group and Didier Grumbach.

[75] In 2016, Mugler created and directed the music video and staging for San Marino's Eurovision Song Contest entry "I Didn't Know" performed by Turkish singer Serhat.

[76] Despite retiring from his brand in 2003, he made the exception to design under his name "House of Mugler" for the Met Gala in 2019 and for Kim Kardashian.

[79][80] During the period of the pandemic, Mugler skipped runways for video shows that were co-created with DIS magazine's spin-off, Torso Solutions.

The homage was dancing feature by prima ballerina Maria Kochetkova and vogueing superstar Barbie Swaee.

The runway featured models Adut Akech, Paloma Elsesser, Eva Herzigova, Ziwe, Arca and Memphy.

[82] An image was shown on an extra-large TV screen flanked by a staircase in the middle of the runway fusing digital with IRL.

Fans of the fragrance include Diana Ross, Barbara Walters, Eva Mendes and Hillary Clinton.

[91] In later years, Mugler's vintage designs saw a significant resurgence among celebrities, including Lady Gaga in the music video for "Telephone", and Cardi B who worked with Mugler, often wearing his vintage designs on red carpets and music videos, as well as mentioning the brand in the song "Wild Side".

A motorcycle accident involved steel cables which saw Mugler have a piece of metal removed from his leg.