Mary O'Halloran passed away in the early morning hours of December 2, 2020, after a courageous battle with cancer. She was surrounded by her family. Mary was born on February 3, 1935, in Fort Loramie, Ohio, to Edward and Agnes (Gariety) Barhorst and grew up with her nine brothers and sisters on a farm. Mary graduated from the Good Samaritan Hospital School of Nursing in 1956. She practiced as a nurse and met William O'Halloran, from Brooklyn, New York. They were married on December 28, 1957, and moved to St. Louis where Bill went to medical school and they started their family. They returned to Dayton. Bill went into family practice in Beavercreek and Mary ruled the home front. Mary and Bill enjoyed the Lake of the Woods in the summers, visits to New York and yearly fishing trips with family to Canada. They took cooking lessons. They religiously followed Dayton Flyer basketball, were longtime season ticket holders, and attended the National Invitational Tournament in New York City in 1968. After Bill's death in 1991, Mary returned to nursing, working for many years as an R.N. at Oak Creek Terrace in Kettering, Ohio. Mary was multi-talented. She planted spectacular flower and vegetable gardens. She loved to watch birds. She took up painting. Mary was generous with her time and treasure. She loved spending Christmas and holidays with family. She thought nothing of jumping in her car and driving to visit. She really loved babies. Mary was a devout Catholic and longtime member of St. Luke's Church in Beavercreek, Ohio. Mary is preceded in death by her husband, William O'Halloran, M.D., and Edward and Agnes Barhorst, Virgil and Beverly Barhorst, Lenore and Albert Otte, Ruth and Alvin Jutte, Leroy Lochtefeld, Leonard Barhorst and Richard Knee. Mary is survived by her siblings and their spouses; Thomas and Bernice Barhorst (Anna, OH), Carol Lochtefeld (Sidney, OH), Barbara and Larry Francis (Russia, OH), Edward and Alice Barhorst (Sidney, OH), Jane and Vernon Monnin (Covington, OH); Bill's sister, Ann O'Halloran Knee (Wilmington, DE); her five children and their spouses, Matt and Tara O'Halloran (Beavercreek, OH), Julia and Tom Hurney (Charleston, WV), Laura and Joe Wagner (Kettering, OH), Phil O'Halloran (Beavercreek, OH), Katie and David Kegg (Cincinnati, OH); her grandchildren, Tiara, Brandon, James, Andrew, Ashton, Grace, Eleanor, Jack, Will, Olivia, Ben and Sam; and great-grandchildren, Isabelle, Lilli and Skylar. The family will have a private ceremony and burial and plans a memorial celebration once the pandemic passes. In lieu of flowers, please consider a donation in Mary's memory to: Dayton Food Bank or the St. Vincent dePaul Society. Condolences can be expressed to the family at www.tobiasfuneralhome.com.