Pauline MacMillan Keinath Net Worth

Pauline MacMillan Keinath has an estimated net worth of $8.4 billion, according to Forbes Real-Time Billionaires, Pauline MacMillan Keinath profile (figures as of October 20, 2026). That is up from $6.9 billion in 2019.

Pauline MacMillan Keinath is known for her stake in Cargill, a major food and agriculture company in the United States. Forbes says she is believed to be the company’s largest shareholder, with an estimated 13% stake. Her wealth is tied to a family business with deep roots in grain trading and food production. Cargill grew far beyond its starting point and now operates across food, agriculture, financial, and industrial divisions.

Her fortune comes from long family ownership in Cargill rather than from building a separate public brand or company. Forbes notes that her great-grandfather, W.W. Cargill, started the business in 1865 as a single grain warehouse at the end of an Iowa railroad line. The family still owns roughly 90% of Cargill. In 2025, the company posted $154 billion in sales, showing the size of the business behind her wealth.

How Pauline MacMillan Keinath makes money

Keinath’s money comes from her ownership in Cargill. Forbes says she is believed to hold an estimated 13% stake, making her the company’s largest shareholder. Cargill is in the Food & Beverage industry, but its business reaches across several areas, including agriculture, financial services, and industrial operations. That broad base matters because her wealth rises and falls with the value of one very large private company.

Cargill has remained a family-controlled business for generations. Forbes notes that the family still owns roughly 90% of the company. Her late brother Whitney MacMillan was the last family member to serve as CEO, and he retired in 1995. That helps explain how the family’s role changed over time. The operating business continued to grow, while family members like Keinath remained tied to it through ownership rather than day-to-day management.

How Forbes' estimate has changed

Forbes has shown meaningful swings in its estimate of Keinath’s fortune over the years. It put her net worth at $6.9 billion in 2019, then $4.8 billion in 2020. The estimate later climbed to $8.8 billion in 2022, before settling at $7.3 billion in 2024. Those moves fit the reality of a private-company fortune tied to the value of a large business in food, agriculture, finance, and industry.

The most recent Forbes numbers also show that changes can happen quickly. Forbes valued her at $9.5 billion on the 2026 World’s Billionaires List. On Forbes’ real-time billionaires tracker, the estimate was $8.4 billion as of October 20, 2026. Cargill’s scale helps explain why the totals stay high. Forbes says the company had $154 billion in 2025 sales, giving her stake a very large base of underlying business activity.