School Mourns Beloved Teacher
St. Mark’s School of Texas mourns the loss of long-time faculty member Bill Marmion, who passed away on March 29, 2025.
"Bill was a man of keen wit, intelligence, and thoughtfulness," said Eugene McDermott Headmaster David W. Dini. "He was a loving father and husband, always speaking with joy and pride about his family. He cared deeply for others and was fully invested in the lives of Marksmen on every corner of the campus."
Bill joined the St. Mark’s faculty in the fall of 1985 and faithfully served the School in various roles for more than 30 years until his retirement in 2016. Throughout his long and meaningful tenure, Bill taught Ancient and Medieval History and Religion, AP Economics, and AP U.S. History and served as Chair of the History and Social Sciences department. He coached in both the Middle and Upper Schools in the fall, winter, and spring, constantly making known his passion for sports and its importance in the growth and development of Marksmen. Among many other contributions, Bill served as Co-Chair of the committee that established the St. Mark’s Middle School Humanities program.
Prior to joining the St. Mark’s community, Bill served as a teacher, coach, department chair, division director, and chaplain at independent schools, including the Emma Willard School, Bryn Mawr School, and St. Christopher’s School. He earned undergraduate and graduate degrees from Washington & Lee, Harvard University, and Episcopal Divinity School, with Phi Beta Kappa honors.
Bill is survived by his wife and St. Mark's faculty member Nancy Marmion, and daughters Elizabeth and Katherine.
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"Bill was a man of keen wit, intelligence, and thoughtfulness," said Eugene McDermott Headmaster David W. Dini. "He was a loving father and husband, always speaking with joy and pride about his family. He cared deeply for others and was fully invested in the lives of Marksmen on every corner of the campus."
Bill joined the St. Mark’s faculty in the fall of 1985 and faithfully served the School in various roles for more than 30 years until his retirement in 2016. Throughout his long and meaningful tenure, Bill taught Ancient and Medieval History and Religion, AP Economics, and AP U.S. History and served as Chair of the History and Social Sciences department. He coached in both the Middle and Upper Schools in the fall, winter, and spring, constantly making known his passion for sports and its importance in the growth and development of Marksmen. Among many other contributions, Bill served as Co-Chair of the committee that established the St. Mark’s Middle School Humanities program.
Prior to joining the St. Mark’s community, Bill served as a teacher, coach, department chair, division director, and chaplain at independent schools, including the Emma Willard School, Bryn Mawr School, and St. Christopher’s School. He earned undergraduate and graduate degrees from Washington & Lee, Harvard University, and Episcopal Divinity School, with Phi Beta Kappa honors.
Bill is survived by his wife and St. Mark's faculty member Nancy Marmion, and daughters Elizabeth and Katherine.
St. Mark’s School of Texas
10600 Preston Road
Dallas, Texas 75230
214-346-8000
Dallas, Texas 75230
214-346-8000
About Us
St. Mark’s School of Texas is a private, nonsectarian college-preparatory boys’ day school for students in grades 1 through 12, located in Dallas, Texas. St. Mark’s aims to prepare young men to assume leadership and responsibility in a competitive and changing world.
St. Mark’s does not discriminate in the administration of its admission and education policies on the basis of race, color, religion, sexual orientation, or national or ethnic origin.
St. Mark’s does not discriminate in the administration of its admission and education policies on the basis of race, color, religion, sexual orientation, or national or ethnic origin.
