School Leadership

St. Sebastian’s is blessed by an experienced and talented team of leaders on our Board of Trustees and Administration.

Brendan W. Sullivan, Head of School

Brendan W. Sullivan began his tenure as St. Sebastian’s tenth Head of School on July 1, 2024. Brendan is a dedicated educator who applies his vast experience and passion for St. Sebastian’s mission to lead the School to ever greater levels of excellence. Joining the faculty in 1994, he has served St. Sebastian’s as a beloved and well-respected science teacher, coach, Athletic Director and Dean of Students. Brendan earned a BA at Princeton University and an MA at Wesleyan University. He is married to Rebecca Sullivan, a Public Relations Director. The Sullivans have three children: Eliza, Class of 2025 at the College of the Holy Cross; Joseph, a member of St. Sebastian’s Class of 2025; and Patrick, the Class of 2029.

Senior Administrative Team

The administrative team works with Mr. Sullivan, under the direction of the Board of Trustees, to articulate and advance our most important mission.