Father Grennan was born on December 28, 1924, in Jewell County, Kansas, the son of William J. and Mary Agnes (Doyle) Grennan. He grew up in Jewell County north of Beloit, Kansas and also lived in Cloud County west of Jamestown, Kansas. He attended high school for 2 years at Jamestown High School before going to the seminary in St. Louis, Missouri. As a young man he worked summers custom cutting wheat harvests for his brothers John and Michael, traveling from Texas to Montana.
He was ordained on May 13, 1951, and that same year took his first assignment as parochial vicar at St. Michael Parish in Collyer, Kansas. He served 70 years as a priest for the Catholic Diocese in Salina. He served in WaKeeney, Hill City, Delphos, Glasco, Esbon, Mankato, Smith Center, Oakley, Manhattan and Plainville. He was assigned to St. Mary’s Catholic Church in Russell, Kansas from 1983 to 1993 and later served in Stockton and Logan. In 2001, he retired and moved back to Russell. Even though he had officially retired, his great passion was to serve the Lord and the church. He continued to serve by helping at the St. Mary Queen of Angels Catholic Church in Russell. He ministered at nursing homes, hospitals as well as traveling the diocese helping serve other parishes as needed. His second great passion was fishing, and when he was not helping at church, you could always find him heading to the lake to fish with his friends Father Charlie Steier and Don Fisher.
Surviving family include his sister Polly Champlin of Mead, Colorado; sister in-law Teresa Grennan of Concordia, Kansas and many nieces and nephews. He is also survived by his longtime caregiver and friend Patricia Staab of Russell, Kansas.
He was preceded in death by his parents, five brothers John, Frank, Tom, Mike and Bill Grennan; and sisters Sister Rose Grennan, Loretta Cady, Marie Stover, Margaret Daily and Kathleen Williams and an infant brother. A celebration of the funeral mass will be held at 11 A.M. on Thursday, February 24, 2022, at the St. Mary Queen of Angels Catholic Church in Russell, Kansas. Burial will follow at the St. Mary Catholic Cemetery in Russell. Vigil and rosary service will be held at 7 P.M. on Wednesday, February 23, 2022 at the church. Visitation will be from 9 A.M. to 5 P.M. Wednesday, February 23rd at the Pohlman-Varner-Peeler Mortuary in Russell. Memorials may be given to the St. Mary Queen of Angels Catholic Church and sent in care of the mortuary. Pohlman-Varner-Peeler Mortuary of Russell, Kansas, is in charge of the funeral service arrangements.