By Marc Horowitz 7 minute 06/11/2026 Matt McGrath as Mister Halston. At the height of his powers, there was no one more fabulous than Halston. With apologies to Ralph Lauren, Calvin Klein, Diane von Furstenberg and other fashion industry titans, Halston occupied a rarefied perch as arguably the most influential American designer of the 20th century. Effortlessly chic, Halston’s aesthetic helped define not only the visual style of the 1970s, but also the zeitgeist of the era.