She served as executive director of the Council of Fashion Designers of America (CFDA) from 1991 to 2001, during which time she created what is now known as New York Fashion Week. In 1993, she launched the initiative to organize, modernize, and centralize a platform for American designers to showcase their collections. Initially called “Seventh on Sixth,” for 19 years, NYFW presented the shows of America's leading and emerging designers in tents in Bryant Park. As senior vice president of IMG Fashion, she expanded the Fashion Week concept to cities including Miami, Los Angeles, Berlin, Moscow, Mumbai, Sydney, and Melbourne.  She left IMG in 2010 to launch her own consultancy, Fern Mallis LLC.

Beyond her role in building NYFW, Mallis is the creator and host of the acclaimed conversation series Fashion Icons with Fern Mallis at the 92NY, now in its sixteenth year.  She has lead in-depth interviews with over 70 leading designers and industry professionals, such as legends Calvin Klein, Tom Ford, Donna Karan, Valentino, Tom Ford, Victoria Beckham, and Leonard Lauder. This series has produced two books published by Rizzoli, Fashion Lives: Fashion Icons with Fern Mallis, Volumes 1 and 2. She has also been a prominent television personality, appearing on Project Runway, serving as weekly judge on Bravo’s The Fashion Show, and as a guest mentor on The Tamron Hall Show, among others.

Mallis was inducted into Business of Fashion’s inaugural BoF 500 Hall of Fame in 2014 and has received numerous industry honors, including lifetime achievement awards from the Pratt Institute, FIT, Fashion Group International, the Accessory Council, and DIFFA.