Mary Ann Gilleran

Mary Ann Gilleran (nee Sweeney), 88, of Oklahoma City passed away peacefully on May 8th, 2026. She was born on March 1st, 1938, in El Reno, OK, Mary Ann was the youngest child, and only daughter, of Eugene and Veronica (Gappa) Sweeney. She loved her childhood on the farm in Union City, OK, where her family raised cattle and grew corn, wheat and cotton. It was a life with both hard work and great memories of her loving parents and brothers about whom she spoke with much fondness.

Mary Ann attended St. Joseph Catholic grade school and graduated from Union City High School in 1956. Mary Ann moved to Oklahoma City that year and enrolled in the nursing program at St. Anthony Hospital. She received her nursing diploma in 1959 and made a multitude of wonderful friends while pursuing her education.

With her license in hand, Mary Ann enlisted in the United States Air Force and was stationed in Whiteman AFB. The stories Mary Ann shared with her daughters about those years working as an RN in the Air Force were fascinating and demonstrated the strength and courage that she possessed. She was a farm girl from a tiny town in central Oklahoma, yet she jumped into this adventure with enthusiasm. Eventually, Mary Ann achieved the rank of 1st Lieutenant, graduated from the Flight Nurse program of the School of Aerospace Medicine and was sent to Misawa AFB in Japan.

Mary Ann met Captain John (Jack) B. Gilleran, MD while stationed in Misawa and the two were married in Tokyo in 1964. She became a mother for the first time while in Japan and received an honorable discharge from the Air Force in 1965. Mary Ann and Jack eventually settled in Oklahoma City after a brief period in California. Two more children joined the family and Mary Ann immersed herself into motherhood with the same energy and attention she had given her career. She was a loyal and loving wife and mom. She invested all of herself into her family. There wasn’t a boo boo she didn’t bandage, a broken heart she wouldn’t soothe, a sporting event she would miss, an opportunity on the dance floor she would skip, or a trip she wasn’t willing to take. She was simply the best, and her legacy will shine on through the incredible family she built.

Marry Ann was preceded in death by her parents, her brother Bryan Sweeney, her brother and sister-in-law Leon and Vera Mae (Sanders) Sweeney. She is survived by her husband of 62 years, Jack Gilleran, as well as her daughters Siobhan and husband Jeff Dixon of Tulsa, Briana and husband Andy Allen of Oklahoma City, Shaunagh and husband Jim Gibbs of Oklahoma City, her sister-in-law Mary Ann (Brown) Sweeney of Stillwater, her cousin Mary Helen (Gappa) Wagner of Oklahoma City, her grandchildren Aryn and husband Austin McCloud of Kansas City, Eilise and husband Miguel Rosendo of Spokane, Bridget Dixon of New Orleans, Rylie Gibbs, Rhett Gibbs, Brody Gibbs, Ian Allen and Ava Allen all of Oklahoma City, and great granddaughter Romee Rosendo of Spokane, and a large family of cousins, nieces and nephews who she adored.

A Memorial service to celebrate Mary Ann’s life will be 2:00 PM Friday May 15th, 2026 at Smith and Kernke N. May Ave, 14624 N. May Ave. Oklahoma City, OK 73134.