Pauline MacMillan Keinath is an American businesswoman, the billionaire heir to Cargill, Incorporated, the largest privately owned company in the U.S. and a global behemoth in food, agriculture, and commodities. Her colossal wealth is generational, tied to the Cargill-MacMillan family, which owns roughly 88 percent of the company.

Keinath's career is defined by generational stewardship and fiduciary oversight of the complex family assets. She is the great-granddaughter of W.W. Cargill, the founder. Her structural role is tied to managing the family's assets, focusing on long-term asset hold and sustainable business practices.

• Cargill, Incorporated (Heir & Major Shareholder): The foundational source of her wealth, the largest privately owned company in the U.S., dominating food, agriculture, and commodities (sales estimated at $154 billion in 2025).
• Family Governance: She is one of 23 members of the Cargill-MacMillan family who collectively control the company.
• Investment Strategy: Her philosophy is rooted in long-term asset preservation and conservative financial management in the essential food and commodity sector.
• Privacy: The family maintains a notoriously low public profile, emphasizing private control.

Pauline MacMillan Keinath's structural role is centered on fiduciary stewardship of her inherited assets, ensuring the long-term, stable management of the Cargill empire. The company's strategic genius lies in its commitment to private ownership and prudent management, shielding the massive enterprise from public market pressures. Her wealth is secured by the colossal, long-term, stable profitability of the global agri-commodities supply chain.

She is based in St. Louis, Missouri, and maintains a quiet profile, focusing on her family interests and the long-term governance of the company.

Pauline MacMillan Keinath's social impact is structural, stemming from Cargill's role as the world's largest agribusiness company, which is foundational to global food security and supply chains. Her family's foundation (the Cargill-MacMillan Foundation) supports various educational and community initiatives. Her structural contribution is tied to the successful generational stewardship and long-term asset preservation of a colossal private industrial fortune.

Her personal philanthropy supports various community and educational initiatives.

Pauline MacMillan Keinath maintains the extremely discreet, low-profile style characteristic of the Cargill-MacMillan family. Her attire is typically conservative and unostentatious. Her aesthetic reflects stability and quiet, established authority, typical of a highly private billionaire.

Residing in St. Louis, Missouri, her luxury is the immense security and financial reward derived from her multi-billion dollar fortune. Her life is dedicated to financial stewardship, investment strategy, and the long-term management of the Cargill legacy.