John F. Brennan, Jr. Obituary, NEEDHAM, Mass. — John Francis Brennan Jr., a longtime investment professional, devoted husband, father and grandfather, was born into eternal life on August 18, 2026, at the age of 67 at his home in Needham, Massachusetts, surrounded by his loving relatives. He was born July 28, 1959, to Lucy and John F. Brennan Sr. in Central Falls, Rhode Island.
Brennan is survived by his wife of 45 years, Deborah (Fitzgerald) Brennan of Westwood, Massachusetts. He is also survived by his sons, John F. Brennan III and his wife, Jacqueline, and Matthew J. Brennan and his wife, Kayla, as well as his grandchildren Lucy, John IV (Jake), Mary, Calvin, Perry and Tucker. His family also includes four siblings, Donna Boulanger, Karen Bates, James Brennan and Jane Brennan Alves, along with his nephews, grandnephews and in-laws.
His education and early interests aided shape a distinguished career. Brennan attended Saint Phillips Elementary School in Greenville, Rhode Island, before graduating from Lincoln High School with the class of 1977. While in high school, he was an honors student and developed his lifelong love of golf while also participating in track and baseball. He later earned a Bachelor of Science degree, summa cum laude, from the University of Rhode Island College of Engineering in 1981.
After completing his undergraduate studies, Brennan joined the General Electric Manufacturing Management program and continued his education at Stanford Graduate School of Business, where he earned his MBA in 1985. That same year, he commenced his investment career with Massachusetts Financial Services in Boston. During his time at MFS, he rose to become a Senior Vice President and distinguished Portfolio Manager.
In 1999, Brennan co-founded Sirios Capital Management, an investment partnership based in Boston. He led the firm for more than 25 years, establishing a long career in the investment industry while maintaining the values of integrity and dedication that were central to his life.
Beyond his professional accomplishments, Brennan’s greatest joy was his loved ones. He was described as a devoted husband, nurturing father and doting grandfather who treasured time with relatives and friends. Loved ones gatherings at his home were filled with laughter, joy and games of Canasta, where he was often partnered with his father, John Sr. He was also a dedicated parishioner of Saint Joseph’s Parish in Needham.
Brennan remained passionate about golf, playing with his wife, sons, loved ones and friends. He was an avid book collector and had a deep appreciation for nature, reflected in the gardens at his home and the habitats he created for birds and wildlife. His relatives remembered his spirit of love and compassion, unwavering faith, and commitment to charity, integrity and love. He will be dearly missed by his family and by those who were fortunate enough to know him.
Visiting hours will be held at Eaton Funeral Home, 1351 Highland Ave., Needham, on Friday, August 21, from 4 to 7 p.m. A Mass of Christian Burial will be held at Saint Joseph Church, 1360 Highland Ave., Needham, on Saturday, August 22, at 11 a.m., with burial to follow at Newton Cemetery in Newton. In lieu of flowers, donations may be made to the Catholic Schools Foundation or Campaign for Catholic Schools. The loved ones and friends of John F. Brennan Jr. are remembered with sympathy as they honor a life defined by family, faith, friendship, service and lasting contributions to those around him.
