William Frawley graduated from Parsons School of Design in 1983 with a BFA in Fashion Design and worked as a designer for Perry Ellis during the remainder of the decade. In 1989, he began a freelance design career, designing for clients such as Gordon Henderson, Liz Claibourne, Isaac Mizrahi, The Limited, Lantis Eyeware, and 9 West/Jones Apparel Group, where he served as creative director for Anne Klein, among other brands. In 2009, Frawley established his own company, specializing in shoes, bags, and accessories.

In addition to designing, Frawley illustrated Parsons classmate Isaac Mizrahi's comic book The Adventures of Sandee the Super Model (1997) and taught in Parsons' Fashion Design Department.