Alexander was born in South Bronx to Julius and Mary Jenkins and cites his mom as the first person to introduce him to fashion.
As a teenager he turned to modeling when he met the president of Elite Model Management Monique Pillard while dressed in drag. Pillard was so impressed with his look that she signed him to her agency and he walked for designer Jean Paul Gaultier in New York City.
Alexander and Tyra Banks have been friends since he was sixteen years old. Alexander and Banks met backstage at a runway show, and he began to give her walking lessons. Banks coined his title Queen of the Catwalk.
Alexander's career as a runway coach began accidentally; he would coach models backstage with good advice, and eventually became recognized for his skills as a coach. He has been coaching and casting since 1991. He rose to prominence in this field when he coached supermodels Naomi Campbell and Kimora Lee.
After a modeling stint in Tokyo, he eventually decided to settle in Paris, and since 1991, has helped with casting and coaching models for well-known designers such as Hervé Léger, Bill Blass, Valentino, John Galliano, Chanel, Alexander McQueen, and Nina Ricci.
Alexander travels globally for charity events and modeling competitions, he also is a judge on Americas Next Top Model. His expertise is frequently sought after by journalists..
America's Next Top Model
Alexander appeared on every cycle of the popular television program America's Next Top Model as the runway coach to the contestants. He was made a judge starting with Cycle 5, though he still acts as the runway coach.
Alexander's nickname "Miss J" came from Cycle 1 contestant Robin Manning, who often confused Alexander and Jay Manuel, and on several occasions referred to Alexander as "Miss J" by accident because of his flamboyant clothing (Alexander often dresses drag and usually wears a skirt and high heels during runway walking training) and personality. Accordingly, Jay Manuel is referred to as "Mr. Jay", and ANTM contestants often call them "The Jays" or "The Two Jays" when they appear together.
He has also appeared on international versions of Top Model, such as Canada's Next Top Model and Scandinavia's Next Top Model. Alexander appeared on the 4 May 2008 episode of Finland's version of ANTM Suomen huippumalli haussa.
Alexander also is interested in designing and has handmade all his clothes on America’s Next Top Model with the exception of the nurse’s outfit,"I did make the hat and the bag." "All the dresses that you see me wear at the challenges, I actually sit down with a needle and thread, not even with a sewing machine, and make them all by hand. I made the ruffles and everything."