Billionaire Profile
Pauline MacMillan Keinath
Global Rank
#432

Image: Public domain | via Wikimedia Commons

Pauline MacMillan Keinath

CEO, Cargill
US
Real-Time Net Worth
$7.8B
As of December 2025
Age
91
Source
Cargill
Industry
food-beverage
Citizenship
US

Biography

Pauline MacMillan Keinath, a prominent American heiress, is a key figure in the world of food and agriculture, primarily due to her significant ownership stake in Cargill, the largest private company in the United States. Born in 1934, she is the great-granddaughter of William Wallace Cargill, who founded the company in 1865. Her wealth primarily stems from her inherited stake in Cargill, placing her among the wealthiest individuals in the U.S. As of December 5, 2025, her net worth is estimated at $7.8 billion. Keinath resides in St. Louis, Missouri, and has maintained a low public profile throughout her life.

Wealth Over Time

In-Depth Profile

Early Life

Pauline MacMillan Keinath was born on July 31, 1934, in Hennepin County, Minnesota. She is the great-granddaughter of William Wallace Cargill, who founded Cargill in 1865 as a grain storage business in Iowa. Her father, Cargill MacMillan Sr., was also involved in the family business. From a young age, Keinath was connected to one of the most successful private companies in the U.S.

Rise to Success

Keinath's wealth and prominence come from her significant ownership in Cargill. She inherited a substantial stake, estimated to be around 13% of the company. This stake has positioned her as one of the wealthiest individuals in the United States. Her wealth has grown steadily due to Cargill's continued success in the global food and agriculture markets.

Key Business Strategies

Keinath's wealth is tied to Cargill's strategic decisions and performance. Cargill's business strategy has been marked by expansion, diversification, and a focus on integrating various aspects of the agricultural supply chain. The company has invested in food production, commodities trading, and financial services, which has allowed for steady growth over the years. Cargill's history includes adapting to changing economic conditions and global markets.

Philanthropy

While specific details about her philanthropy are not readily available, Keinath is known for her philanthropic efforts and contributions to charitable causes. Her family has been involved in significant charitable giving, and Keinath is expected to have participated in these activities.

Career Milestones

1934

Born

Born in Hennepin County, Minnesota.

1995

Cargill CEO Change

Her brother Whitney MacMillan retired as the last family member to serve as CEO.

2022

Richest Person in Missouri

Recognized as the richest person in Missouri.

Philanthropy & Social Impact

Charitable Giving

Not publicly specified

Undisclosed

Contributes to various charitable causes.

Controversies & Challenges

2021

Political Contributions

Continued support for Josh Hawley, donating $1,900 in the second half of 2021.