Born August 11, 1915, Monsignor Fannon was baptized at St. Patrick, Mount Savage. He attended St. Patrick School before applying to be a seminarian for the Archdiocese of Baltimore.
In 1935, he graduated from St. Charles College Seminary, Catonsville, before moving to St. Mary's Seminary on Paca Street. After graduating in 1937, he spent four years studying theology at St. Mary's Seminary and University, Roland Park, and in 1941, he was ordained at the Basilica of the National Shrine of the Assumption of the Blessed Virgin Mary, Baltimore, by Archbishop Michael J. Curley.
He became administrator of St. Lawrence Martyr, Jessup, and Holy Trinity, Glen Burnie until 1975, when he returned as pastor of St. Lawrence Martyr. Before his retirement in 1983, he served as director of the fund development office for the archdiocese.
Pope John Paul II named the priest a monsignor in 1997.
He passed away on December 5. 2006 at Stella Maris, Timonium.