Michael Stubblefield, Senior Advisor, joined New Mountain Capital in 2026. He is a global chief executive with more than three decades of leadership experience across life sciences, specialty materials, and petrochemicals, serving a diverse range of industrial and healthcare end markets.
From 2014 to 2025, Mr. Stubblefield served as President and Chief Executive Officer of Avantor, a leading global provider of mission-critical products and services to customers in the life sciences, advanced technologies, and applied materials industries. He also served as a member of the Company’s Board of Directors. During his tenure, he led the company’s growth and strategic transformation, including executing its public listing.
Prior to joining Avantor, Mr. Stubblefield was a Senior Expert in the Chemicals Practice at McKinsey & Company. Earlier in his career, he held senior leadership roles at Celanese Corporation, including Vice President and General Manager of Advanced Engineered Materials and Chief Marketing Officer.
Mr. Stubblefield earned a Master of Business Administration from Texas A&M University–Corpus Christi and a Bachelor of Science degree in Chemical Engineering from The University of Utah.