Thomas Gleason Gallagher, III

Thomas Gleason Gallagher III, affectionately known to family and friends as “Gleason,” passed away peacefully on July 16, 2026, at the age of 73, surrounded by the love of his family.

Born on June 4, 1953, Gleason was the beloved son of the late Thomas Gleason Gallagher Jr. and Isabell (Maguire) Gallagher. He was also predeceased by his cherished sister, Sharon Gallagher. He is survived by his loving sister, Lacey Cronin and her husband, Bob, of South Natick.

A proud graduate of St. Sebastian’s School in Needham and Boston College, Gleason remained deeply devoted to both institutions throughout his life. His love for St. Sebastian’s and Boston College never faded, and he treasured the lifelong friendships and values they instilled in him. His Catholic faith was the foundation of his life, guiding him with humility, compassion, and unwavering devotion.

Professionally, Gleason was a gifted leader whose career reflected the same values that defined his life: integrity, loyalty, vision, and an unwavering commitment to people. Over more than four decades, he served in executive leadership positions throughout the telecommunications and electronics industries, leading worldwide sales organizations. Known for transforming organizations and mentoring future leaders, Gleason earned the admiration and lasting friendship of colleagues across the industry. While he took pride in the companies he helped build, he was far prouder of the relationships he formed and the people whose careers he helped shape.

Along with his professional accomplishments, Gleason measured success not by titles or accolades, but by the people he loved and the lives he touched. He possessed a rare gift for making everyone feel welcome. A legendary storyteller with an infectious sense of humor, he could captivate any room. Loyal beyond measure, he was the friend who always showed up, the mentor who offered thoughtful advice, and the father figure so many were fortunate to have in their lives. His kindness, generosity, wisdom, and authenticity left an indelible mark on everyone who knew him.

Gleason found joy in life’s simple pleasures, coaching and cheering on local sports teams, spending time with family and friends, and never passing up the opportunity to share a great story. He took great pride in watching generations of young people grow, compete, and succeed.

Gleason leaves behind his beloved wife of 50 years, Mary (Kelly) Gallagher, who was the greatest love of his life. They shared a marriage defined by unwavering love, deep partnership, and enduring devotion. Their relationship was an inspiration to all who knew them.

He also leaves behind his devoted children, Kelly (Gallagher) Ryan and her husband, Chris, of Concord; Lacey (Gallagher) Plunkett and her husband, Kevin, of Hingham; and Thomas Gleason Gallagher IV and his wife, Diana, of Norwell.

He was the proud and devoted “Pops” to John, James, Patrick, Mary Kate, Sean, Kevin, Maddie, and Thomas Gleason Gallagher V (“Tommy”), each of whom brought immeasurable joy to his life. He is also survived by many beloved nieces, nephews, cousins, and dear friends, all of whom were blessed by his unwavering love, loyalty, and generous spirit.

Family and friends are invited to celebrate Gleason’s life during visiting hours at Holy Family Parish, 12 Monument Square, Concord Center on Wednesday, July 22, from 4:00 to 7:00 p.m. A Funeral Mass will be celebrated at Holy Family Parish on Thursday, July 23, at 10:00 a.m., followed by burial at Westview Cemetery in Lexington.  Please click here to access the church live stream, for those who wish to attend the service remotely.

In lieu of flowers, the family invites memorial contributions to the Gleason Gallagher Game Day Fund (link to follow), established to help grandparents, seniors, and individuals with mobility challenges attend the sporting events and activities of the children and grandchildren they love. Additional details regarding the fund will be shared by the family.

Gleason’s greatest legacy is found in the countless lives he touched. He showed us how to love unconditionally, lead with integrity, remain fiercely loyal, laugh often, and put family above all else. His example will continue to guide those who knew and loved him, and his stories, wisdom, and unmistakable presence will be profoundly missed but forever remembered.

Arrangements have been entrusted to Dee Funeral Home & Cremation Service of Concord.