After meeting her husband Tom Bugbee, Lhuillier began planning her wedding, which was her first foray on the bridal market, and thought it needed updating. She could not find any modern dresses, and did not like the excess of lace. She used her fashion degree to create dresses for her relatives and bridal party. After the wedding, there were business cards left for her. It was then when she realized she could make a business out of her beautiful bridal designs.
Her husband Tom joined the company as CEO. She opened her first retail store in 2001. In 2004 she drew wide notice for her wedding dresses for Britney Spears and Emmy Awards dresses for Jamie-Lynn DiScala and Allison Janney, among others. She opened a Los Angeles “flagship” store on Melrose Place in 2007, and added a New York store in 2012. Her collections now include ready-to-wear, evening gowns, bridal, bridesmaids, linens, tableware, fine paper, and home fragrances. In 2016, in collaboration with Pottery Barn Kids, Lhuillier launched a line for babies and kids.
The collection featured over 120 items of home furnishings for the nursery, bedroom, and playroom. Lhuillier has become especially known for her celebrity wedding and red carpet gowns. Her list of clientele includes Blake Lively, Demi Lovato, Gwyneth Paltrow, Reese Witherspoon, Michelle Obama, Emma Stone, Jennifer Lopez, Taylor Swift, Melania Trump, and Katy Perry.