Simmons has walked the runway for fashion houses such as Fendi and Valentino and appeared on the covers of Vogue and Elle.

[3][4] Growing up in the northern St. Louis suburb of Florissant, Missouri, Simmons was a frequent target of bullying at school.

[5] Because of her height (5'10" by age ten) and multiethnic background (she is partial African-American on her father's side and Japanese-Korean on her mother's), Simmons struggled to find confidence and felt, in her own words, "different.

Kollock then sent Simmons to Paris, where she would soon find favor with fashion industry leaders and begin her modeling career in earnest.

The celeb and musician friends that supported the brand also inspired it - really innovative women who pushed the world forward to embrace the urban lifestyle when many in the business and in society at large did not have the vision or foresight [to do so].

[21] Baby Phat's commercial success (the company was at one point estimated to be worth in excess $1 billion[22]) and cultural impact ultimately drove the expansion of Phat Fashions into a multitude of new product categories that included jewelry, handbags, footwear, swimwear, outerwear, infant accessories and fragrance, all of which were distributed on a global scale.

The following year, Simmons announced her new position as President and Creative Director of JustFab, a personalized shopping website.

[23] The namesake women's wear line offers upscale apparel at entry-level price points in the American designer category.

Following development, KLS by Kimora Lee Simmons was marketed for nationwide placement within the designer arena at high-end luxury retailers such as Bloomingdales, Lord and Taylor and Farfetch.

Young people have an appetite for design with a purpose and place importance on a need for messaging that is similar to what Baby Phat represented in its prime and still can today.

"[26] Simmons built a portfolio of investments in fashion, skin care, consumer goods and technology like Codage, an advanced technical skin care line based in France; Pureform Global, the first manufacturer of non-cannabis, non-hemp all natural CBD products; and Celsius, a "clean energy" negative calorie drink acquired in 2015.

[36] In 2023, Simmons filed a lawsuit against Leissner claiming that "shares worth about US$93 million that he was ordered to forfeit as part of his 1MDB guilty plea actually belong to her".

[37] In 2008, Simmons lent her voice and image to PETA in support of the organization's Be an Angel to Dogs campaign, which called for more humane consideration in the care and keeping of household pets.

Additionally, Simmons is an active supporter of amfAR, The G&P Foundation, Keep a Child Alive, and the Hetrick-Martin Institute.

[42] As of 2018, Simmons has done humanitarian work in support of refugees and in-crisis migrant women and children fleeing violence, persecution and natural disasters in their home countries.

As Lead Global Ambassador for intimate health nonprofit The Unmentionables,[43] Simmons has helped to fund the distribution of reusable female hygienic products and supplies to communities of migrant and refugee women entering Europe through Greece.

Kimora: House of Fab ran for one season with Simmons starring in and executive producing on each of the series's eight episodes.

The female empowerment lifestyle manual received favorable reviews from such publications as the Washington Post and Boston Globe.

Dressed in a faux chinchilla floor-length coat and hot pink thigh-high boots, mini skirt and peplum top, the doll was created under the direction Simmons to epitomize the brand identity she has cultivated across her life's many endeavors.

Simmons has appeared in multiple roles in television and films including Beauty Shop, Brown Sugar, and Waist Deep.