19 Celebs Who've Stripped Down to Their Calvins, to Honor Calvin Klein's Birthday

Calvin Klein is, without a doubt, one of the leading men in American fashion design, playing an integral role in popularizing minimalistic attire. And, not only were his designs incredibly popular in the 1980s and '90s, but during that time, Calvin Klein's famous ad campaigns helped launch the careers of many Hollywood A-listers, including Brooke Shields, Kate Moss, and, of course, Mark Wahlberg.

Today, Klein (above) turns 73 and his iconic designs are no less popular now than they were a decade ago. In fact, the brand has seen a major comeback in recent years as many celebs have been seen sporting Klein’s traditional undergarments, er, tighty whities, online. Often using the hashtag #mycalvins, everyone from Chrissy Teigen to Fergie to recent CK campaign models, Justin Bieber and Kendall Jenner, have been known to share their love of Calvin Klein underwear pretty, um, candidly via Instagram. To see for yourself, scroll through the sultry pics below featuring some of our favorite celebs in their beloved Calvins.