San Diego Business Journal

Position/Status: Philanthropist

Estimated Net Worth: $3.7 billion

Age: 53

Residence: Rancho Santa Fe

Source of Wealth: Heir to founders of the Cargill company

Gwendolyn Sontheim Meyer is an heiress to the agribusiness Cargill Inc., the largest privately held company in the U.S. with estimated annual sales of about $130 billion. Cargill sells food, processes crops, trades commodities, sources ingredients and offers financial risk management. Cargill operates in more than 60 countries and employs more than 120,000.

The Cargill-MacMillan families still own an estimated 88 percent of the company. Meyer owns 9 percent of the company, Forbes estimates, but she is not believed to be active in the company’s operations.

Meyer’s most visible activities are in the equestrian community. She lives in Rancho Santa Fe and competes and trains horses in show jumping and dressage. According to, Meyer’s stable has purchased prize-winning horses for Olympic medalists Guenter Seidel and Beezie Madden.

Meyer serves on the board of Feeding America San Diego and is associated with the Aquila Foundation for Education.