Bernhard Willhelm studied fashion design at the Royal Academy of Fine Arts in Antwerp, where he gained experience working with designers such as Walter van Beirendonck, Alexander McQueen, Vivienne Westwood, and Dirk Bikkembergs. In 1998, he founded his fashion house in collaboration with Jutta Kraus, debuting their first womenswear collection in 1999 and a menswear collection in 2000.

In 2001, Willhelm appeared nude in the first issue of Butt magazine, photographed by Turner Prize-winning photographer Wolfgang Tillmans. In 2002, he moved his design studio from Antwerp to Paris and served as creative director for the Italian fashion house Capucci until 2004. His work continued to receive international attention.

Willhelm also ventured into filmmaking, collaborating with Nick Knight on Men In Tights, which accompanied his Autumn/Winter 2008-09 menswear collection, and co-producing Red Rose Pink Donkey with Dirk Bonn, shown at the Athens Biennale. He designed costumes for Björk’s Volta album cover and tour in 2007, as well as for the R.W. Fassbinder play Die bitteren Tränen der Petra von Kant at the Deutsches Theater in Berlin.

From 2009 to 2014, Willhelm headed the fashion department at the Universität für Angewandte Kunst in Vienna. In 2011, he moved his design team to Puerto Vallarta, Mexico, and then to Los Angeles in 2013. That same year, he presented his Autumn/Winter 2013-14 collection as a dance performance with Josh Johnson and The William Forsythe Company in Frankfurt.

Willhelm engaged in several commercial collaborations, including working with Camper on footwear from 2008 to 2015, and with Mykita on sunglasses starting in 2009. He also collaborated with Henzel Studio on rugs and pillows inspired by his exhibition BERNHARD WILLHELM 3000: When Fashion Shows The Danger Then Fashion Is The Danger at MOCA in Los Angeles.

His notable exhibitions include BERNHARD WILLHELM Jutta Kraus at the Groninger Museum in the Netherlands (2009), BERNHARD WILLHELM: HET TOTAAL RAPPEL at the MOMU Fashion Museum in Antwerp (2007), and BERNHARD WILLHELM 3000 at MOCA Los Angeles (2015).

In 2018, Willhelm returned to Paris after time in the Italian Alps. In 2023, he paused his regular work on seasonal collections, choosing instead to focus on collaborations with brands like Mykita and Grounds, shifting his focus towards specific projects.