Tracy Chambers (Diana Ross), an aspiring fashion designer from the slums of Chicago, dreams of becoming one of the world's top designers. Her ambition leads her to Rome, where she becomes a popular fashion model, "Mahogany," and eventually launches her own successful fashion label. Along the way, she must choose between her man, Brian (Billy Dee Williams), and her newfound success, as well as confront her own self-sabotage and body image issues with the help of a new benefactor, Count Christian Rosetti (Jean-Pierre Aumont).