Leo Joseph McCarthy, MD, FRCP Edin/Ire, 85, passed away peacefully at his home in Indianapolis, Indiana, on May 12, 2025. He was lovingly cared for by his devoted wife and constant companions—his beloved dogs—throughout his final illness. Leo succumbed to complications of metastatic skin cancer, supported with great compassion by hospice caregivers whom the family gratefully calls “angels.”
Leo J. McCarthy, M.D., Professor Emeritus of Pathology and Laboratory Medicine, was the Director of Transfusion Medicine at the Indiana University School of Medicine for three decades. In 1991, he became a Fellow in the Royal College of Physicians of Ireland, and in 1994 a fellow in the Royal College of Physicians of Edinburgh.
Dr. McCarthy created and endowed the annual Leo J. McCarthy, M.D. Lectureship in Transfusion Medicine in 1997 at IU School of Medicine, where he also established an accredited fellowship in Transfusion Medicine in collaboration with the Indiana Blood Center. At the 1997 Indiana Association of Blood Banks he received the Victor H. Muller Award to acknowledge his contributions to transfusion medicine, blood banking, and transfusion services.
The History of Medicine Collection is located on the third floor of the Ruth Lilly Medical Library, Room 307 of the IB building on the IU School of Medicine's Indianapolis campus. Thanks to a generous gift in 2015, the newly remodeled room was named for Dr. Leo J. McCarthy, M.D., Professor Emeritus of Pathology and Laboratory Medicine and former Director of Transfusion Medicine at the Indiana University School of Medicine.
Leo had a great love of life—people, a good joke, travel, his dogs, fitness, and learning. He was known for his wit and unwavering loyalty to those he loved.
He is survived by his wife and soulmate of 43 years, Susan Prenatt McCarthy, and his cousins Warren Filbert, John Filbert, Gregory Snyder, Michael Cruise, Timothy Cruise, Tom Cruise, and Colleen Cruise. He was preceded in death by his mother Marjorie, his maternal grandparents Hank and Stella (Hughes) Cruise, his aunts Barbara Cruise Snyder and Angela Cruise Filbert, his uncle Jack Cruise, and his cousin Patrick Cruise.
A visitation will be held at 10:30 a.m. on Friday, June 6, 2025, at St. Luke Catholic Church, 7575 East Holliday Dr, Indianapolis, followed by a Funeral Mass at 11:30 a.m. Burial will follow at Our Lady of Peace Catholic Cemetery, 9001 Haverstick Rd, Indianapolis.
