Billionaire Profile

Global Rank

#2356

Image: Public domain | via Wikimedia Commons

Martha MacMillan

CEO, Cargill

Real-Time Net Worth

$1.5B

As of December 2025

Age

Source

Cargill

Industry

food-beverage

Citizenship

Biography

Martha MacMillan is an heiress to Cargill, the largest private company in the United States, founded in 1865 by her great-great-grandfather, W.W. Cargill. With an estimated net worth of $1.5 billion, Martha MacMillan's wealth is primarily derived from her stake in the food and agriculture giant. Cargill operates across food, agriculture, financial, and industrial divisions, generating $154 billion in revenue in fiscal year 2025. Her career has been marked by a private life, and an active involvement with the Martha Elizabeth Macmillan Foundation.

Wealth Over Time

Portfolio Holdings

Cargill

In-Depth Profile

Early Life

Martha MacMillan is a member of the Cargill-MacMillan family, a dynasty that has controlled Cargill for over 140 years. Her great-great-grandfather, William Wallace Cargill, founded the company in 1865 as a grain storage business in Iowa.

Rise to Success

Cargill's success grew through strategic partnerships and by expanding during critical periods. After the death of William Cargill, his son-in-law, John MacMillan, steered the company to stability. The family's wealth is significantly tied to their 88% ownership of Cargill. Martha MacMillan does not have an active role in the company.

Key Business Strategies

Cargill's key business strategies include a focus on agricultural commodities, food processing, and financial services. The company has expanded globally and adapted to changing market conditions. While the company is privately held, it reported $154 billion in revenue for fiscal year 2025.

Philanthropy

Martha MacMillan is involved with the Martha Elizabeth Macmillan Foundation.

Career Milestones

1865

Cargill Founded

W.W. Cargill founded Cargill as a grain storage business.

1895

MacMillan Family Involvement

John H. MacMillan Sr. married Edna Cargill, integrating the MacMillan family into the business.

1976-1995

Whitney MacMillan's leadership

Whitney MacMillan, Martha's uncle, served as CEO.

Philanthropy & Social Impact

General Philanthropy

Martha Elizabeth Macmillan Foundation

$0.5M

The Martha Elizabeth Macmillan Foundation gave $546.2k in grants in 2022

Business Philosophy & Leadership

Notable Quotes

""They want to draw the curtain down.”"

Leadership Principles

Family Ownership

Maintaining 88% ownership of Cargill to ensure financial privacy.

Long-Term Vision

Focusing on long-term sustainability and responsible business practices.

Controversies & Challenges

2019

Environmental Concerns

Criticism from environmental groups regarding deforestation and palm oil sourcing.

Ongoing

Business in Russia

Criticism for continuing business operations in Russia after the invasion of Ukraine.