Stephen McGarry Jr.

Stephen McGarry Jr. joined Flagship Pioneering in 2025 as Director, Human Resources Business Partner for Pioneering Medicines. In this role, he serves as a strategic partner to the Pioneering Medicines leadership team, leading the execution of people strategies that enable growth and organizational evolution across talent, culture, workforce planning, and performance.

Prior to joining Flagship, Stephen spent five years at Flagship-founded Seres Therapeutics, where he supported the company’s transition from clinical-stage to commercial-stage following FDA approval of VOWST, the first oral microbiome therapy. Across more than 13 years of experience, Stephen has led organizational effectiveness and culture transformation efforts in high-growth, complex environments, with a strong track record of aligning HR strategy to business needs.

Stephen earned a B.S. in International Business from Northeastern University and a B.A. in European Business from Dublin City University. He holds the Senior Professional in Human Resources (SPHR) certification from the Human Resources Certification Institute.