Kelly, who is of Irish and Italian ancestry, was raised in Port Jefferson Station, New York on Long Island. He graduated from Comsewogue High School in 1987. He attended Boston College and graduated with a degree in communications in 1991; he was president of Boston College's University Chorale. After college, he attained his master's degree in journalism (MSJ), specializing in magazine publishing, from the Medill School of Journalism at Northwestern University in 1993.

Magazines

Before joining as co-host of What Not to Wear, Kelly "hosted a program on Q2 (part of QVC)" and worked as a freelance writer and editor at several publications in New York. Kelly was an editor at Marie Claire and a deputy editor at Mademoiselle, where he contributed under the pseudonym "Joe L'Amour". He later became the executive editor of the Daily News Record, a New York-based weekly men's fashion and retail trade magazine.

TLC

While Kelly was at DNR, the producers at TLC's What Not to Wear decided to recast the original male lead (Wayne Scot Lukas) and approached Kelly. After three auditions, Kelly was chosen as the new co-host, alongside Stacy London. He has described their relationship as "a brother and sister in the backseat of a car on a long car trip."

Kelly is openly gay, but in comparing What Not to Wear with the preceding show Queer Eye ... which pioneered gay men making over people seen as needing fashion advice...the Washington Blade noted some key differences: "[U]nless you have your gaydar on while watching the show, you would have no idea. There's nothing 'gay' about the show and he doesn't really talk about it on air. Viewers trust Kelly's expertise based on the strength of his choices rather than on the 'he's gay and he should know' fashion theory." Kelly married his partner in 2009 at their home in Connecticut.

In 2008 Kelly served as a guest consultant on the TLC reality series Miss America: Countdown to the Crown. He also assisted Mario Lopez during the live pageant telecast.

Books

In September 2005, Kelly and Stacy London co-wrote a book entitled Dress Your Best: The Complete Guide to Finding the Style That's Right for Your Body. In 2008, Kelly wrote Freakin' Fabulous: How to Dress, Speak, Behave, Eat, Drink, Entertain, Decorate, and Generally be Better than Everyone Else.

Fashion

In addition to his books and hosting duties on What Not to Wear, Kelly writes a weekly style column for the Chicago Tribune's RedEye. He's also a national spokesman for Macy's and has a clothing line through the QVC brand Denim & Co, which is known for its simple, classic, "easy-care" designs. In July 2008, his Extended Tab 5 Trousers sold out in seven seconds.He is quoted as saying "Looking good is every woman's inalienable right."