Margaret Baker is a prominent American billionaire and a key member of the Mills family, which founded the medical supplies giant Medline Industries. She belongs to the fourth generation of the family, which has led the company for over a century.

Baker grew up in the Chicago suburbs and was part of the strategic family governance structure that oversaw the company’s massive expansion during the global pandemic. She became an official billionaire in December 2025 following the company's historic Initial Public Offering.

• Core Company: Medline Industries (Medical supplies).
• Role: Major individual stakeholder and family director.
• Family Legacy: Sister of Medline Chairman Charlie Mills and cousin to Director Andy Mills.

Margaret Baker’s professional role has been defined by the long-term stewardship of the family business. Her structural contribution is tied to the board-level management of Medline, the largest privately held manufacturer and distributor of healthcare supplies in the U.S. until its public debut.

She was part of the leadership team that navigated the $30 billion leveraged buyout in 2021, where the family sold a 79% stake to a private equity consortium. Following the December 2025 IPO on the Nasdaq, the company’s market cap soared to over $55 billion, cementing her position among the world's wealthiest individuals.

• IPO Milestone: Medline's debut on Nasdaq in December 2025 with a record valuation.
• Ownership: The extended Mills family continues to own roughly 17% of the company.