Net Worth: $1.8 billion

LAST YEAR: $2 billion
CHANGE: -10%
AGE: 69
RESIDENCE: Malibu
SOURCE OF WEALTH: Inheritance, food manufacturing/distribution, agriculture

MacMillan maintains an estimated 3% ownership in Cargill, which she inherited in 2006 from her father, William Duncan MacMillan. She has no known involvement in the company’s operations. Cargill is the largest private company in the United States and the biggest food company on the planet. Per its annual report, Cargill saw $160 billion in annual revenue for the fiscal year 2024, down from $177 billion the previous year. Annual revenues declined as plentiful crop supplies pushed down prices. Competitors like ConAgra saw their stock prices remain flat year-over-year.

Cargill Stats: The company has more than 160,000 employees in 70 countries.Annual revenue was $160 billion in fiscal year 2024, down from $177 billion the year prior.

Family: MacMillan and her three sisters are among the descendants of Cargill Inc.’s founder William Wallace Cargill. The Cargill/MacMillan family has minted at least 14 billionaires, the most of any family in the world.