Nicole Richie, seen here at an event with boyfriend Joel Madden, designs a jewelry line called "House of Harlow 1960," named after her daughter Harlow Winter Kate Madden.
When he's not making music with Fall Out Boy, Pete Wentz also designs for his "Clandestine Industries" clothing line.
Sean "Diddy" Combs designs lines for men and women under the label "Sean John." The rapper/producer is seen here at a event at the 2008 Cannes Film Festival.
Credit: AP Photo/Matt Sayles
Gwen Stefani, who fronts the band No Doubt and has her own successful solo career, designs handbags for LeSportSac and runs her own line called L.A.M.B.
Credit: AP/The Courier, Eric Swist
In 2001, Jennifer Lopez developed her fashion line, "JLO by Jennifer Lopez." In 2007, she dropped the JLO tag and began selling a line called "JustSweet," but then announced that she would relaunch her namesake line beginning in Fall 2008.
Rapper Eve, seen here at an event on June 4, 2009, launched her clothing line "Fetish" in Fall 2003.
Ashley and Mary-Kate Olsen, pictured here at a 2008 event, co-design a high-end clothing line called The Row, and another one called "Elizabeth & James."
Tennis star Serena Williams, seen here at New York Fashion Week with Vogue editor Anna Wintour, has a clothing line called "Aneres" (her name spelled backwards). Her sister Venus is also a designer and has created pieces for Wilson's Leather.
Credit: AP Photo/Seth Wenig
Rapper Jay-Z, pictured at the 2008 Grammy Awards, designs for Rocawear, a label that caters to both men and women.
Beyonce Knowles, seen here at the 2009 premiere of her film "Obsessed," and her mother Tina both design for their mother/daughter fashion venture called "House of Dereon."
Former supermodel Christy Turlington joined up with athletic wear powerhouse Puma to create a line of yoga-inspired footwear and activewear called Nuala.
Credit: AP PHOTO
Plus-size supermodel Emme gears her namesake label towards voluptuous womem. JCPenney sells a less expensive Emme clothing line called True Beauty.
Rapper Eminem's hip hop clothing line, Shady Ltd., is available at Kohl's department stores.