Martha Stewart

Company: Martha Stewart Living Omnimedia

Age: 77

Net worth: $300 million (£232.3 million) (2018

Martha Stewart grew to stardom as a celebrity chef, publishing a number of cookbooks and writing columns for several magazines. In 1997, the businesswoman centralised all her ventures with the creation of her media company, Martha Stewart Living Omnimedia. She has since delved into TV and radio, and she continues to focus on her cooking success.