Michael Costello (born January 20, 1983) is an American fashion designer and reality television personality. He appeared on the eighth season of Project Runway and the first season of Project Runway All Stars.

Costello started designing clothes at the age of two by drawing dresses on his bedroom walls. At the age of 15, he opened his first store at 286 North Palm Canyon Drive in Palm Springs.It was at his first store in Palm Springs where Costello started making custom pieces for celebrities including Céline Dion, Jennifer Lopez, Toni Braxton, Barry Manilow, Suzanne Somers, Faye Dunaway, Florence Henderson, and more. Costello made headlines for designing a matching hat and dress for rapper Cardi B for Paris Fashion Week. Kylie Jenner wore one of his dresses for her birthday magazine cover and Costello has partied with Lady Gaga. He collaborated with Essie nail polish and designed his own lipstick and eyeshadow shades for Inglot Cosmetics.