Mark Joseph Gleason, Sr.

Mark Joseph Gleason, Sr., passed away peacefully on April 6, 2026, at the age of 87.

A kind and caring gentleman, a role model and trusted mentor, a true and loyal friend, Mark was born and raised in St. Louis, Missouri, the second of Hermine and Thomas Gleason’s six children. He graduated from St. Louis University High in 1956 and from St. Louis University in 1960.

In 1964, Mark married his sweetheart, Kathleen “Kathy” Ryan. Together they built a life, raising their three children, first in St. Louis and later in Hinsdale, a suburb outside of Chicago. 

Mark began his career as an institutional sales trader at A.G. Edwards, went on to A.G. Becker, and ultimately spent the bulk of his professional life at Goldman Sachs. He loved everything about his work, especially the pace and the people. Everyone who worked with Mark – his customers and colleagues alike – knew one thing above all else: He was a man of integrity. 

Mark’s greatest pride and deepest joy was his family. His love was constant, and he had a gift for creating meaning around the small things in family life: Saturday morning errands, cleaning the garage top to bottom, a special dinner in the city, a summer evening frozen yogurt run, a competitive game of gin rummy (a competition of any kind, really), a quiet neighborhood drive, a friendly round of golf, tending burgers on the grill, stringing lights on the Christmas tree, St. Louis Cardinals games, and vacations at the family’s home in Hobe Sound, Florida. As Mark would put it, he was a “happy camper” in just about any setting.

From his first days to his last, everyone who met Mark came to know him for his easy laugh, the twinkle in his eye, and a quick wit that put you at ease and made you feel good. 

Mark is survived by Kathy Gleason, his beloved wife of 62 years; their three children, Mark Jr. (Lou Ann), Tom (Cecilia) and Anne; and four grandchildren, Hannah, Joe, Annika and Aidan. He is also survived by three siblings: Timothy (Maureen), Sister Mary Ann Gleason and Jane Brown (Finley). His brothers Thomas (Sally) and Patrick (preceded into heaven by Nancy) passed away last year. 

Mark was a man of quiet faith. A private family Catholic Mass will be held at a later date. In lieu of flowers, contributions in Mark’s honor can be made to King Bruwaert House.