Dennis J. Callahan

Dennis J. Callahan, of Waltham, died Wednesday, October 8, 2025 at Newton-Wellesley Hospital. He was 88. He was the beloved husband of 61 years of Marie E. (Venesi) Callahan.

In addition to his wife, Marie, he leaves his brother, Paul Callahan of Salem, New Hampshire; his sisters-in-law, Mildred Venesi of Washington, D.C., Barbara Sexton of Cambridge and Anne Phillips of Tampa, Florida and many nieces and nephews and grand nieces and nephews.

Dennis was also a brother of the late Ann Garabedian, Robert and Jeremiah Callahan and Helen Edwards.

Dennis was born on March 29, 1937, in Cambridge, a son of the late Dennis Joseph and Louise M. (Larson) Callahan and was a graduate of Rindge Technical High School.

After that he joined the United States Navy and served for four years in the Caribbean and Mediterranean.

Following his discharge from the service Dennis attended Newman Preparatory School, Wentworth Institute, both in Boston, and Lowell Institute at MIT before embarking on a decades long career as a software engineer with MIT Lincoln Laboratory in Lexington.

A Waltham resident for more than fifty years, he and his wife, Marie, were longtime members of Our Lady’s Parish where Dennis was a member of the church choir. His love of music extended to his membership in the Mishawum Choral Society of Woburn.

For many years Dennis and Marie enjoyed winter vacations to Naples, Florida and summer trips to Ogunquit, Maine. Dennis loved life. He also loved golf, very long walks, the theater, ballet and trips to New York City to attend performances of the Metropolitan Opera. And those special trips to Maui, San Francisco and the Grand Canyon.

Family and friends will honor and remember Dennis’s life by gathering to visit beginning at 10 a.m. on Friday, October 17th in Our Lady Comforter of the Afflicted Church, 880 Trapelo Road, Waltham where his Funeral Mass will be celebrated at 11 a.m. Burial will be private.

Memorial donations may be made to the Salvation Army, 33 Myrtle Street, Waltham, MA 02453 or at https://www.salvationarmyusa.org/