Fr. Kenneth Theisen, OSB

Rev. Kenneth Theisen, O.S.B., a monk of Marmion Abbey, died on August 8, 2025, at St. Patrick’s Residence in Naperville, Il. Fr. Kenneth was born on November 1, 1941. Son of Harry and Marie (Bohr) Theisen, he was the youngest of nine siblings, seven brothers and two sisters. He attended Saint Theresa grade school in Aurora and graduated from Marmion Military Academy in 1959. He attended one year of St. John Vianney Seminary in Elkhorn, Nebraska and entered Marmion Abbey in July of 1960. After his novitiate year, he was a student at St. Procopius College, graduating in 1964. He professed solemn vows August 15, 1964. He spent two years studying theology at St. Procopius Major Seminary. He took a year’s leave of absence, serving as an instructor at Marian Central Catholic High School in Woodstock, Illinois, 1966-67. In 1968 he received a dispensation from his religious vows as a Benedictine monk. For the next ten years he worked in Estes Park, Colorado, overseeing a motel and working with his brother Richard in his roofing business. After discernment, he decided to apply once again for entrance to Marmion Abbey. He was invested as a novice in August of 1980. From 1981-1984, he did his theological studies at Saint Meinrad School of Theology in Indiana. He professed solemn vows on August 6, 1984, and was ordained to the priesthood on December 27, 1984. Father Kenneth then entered a period of holding multiple roles at Marmion Abbey and Marmion Academy. He began teaching assignments in the Mathematics Department of the Academy. For three decades, he established himself as a master teacher and tutor in Algebra and Advanced Math. He also served for several years as golf coach and as the Dean of Men for the Resident Students. At the Abbey, Fr. Kenneth served as Procurator and Prefect of the House, Kitchen Master and Treasurer. He followed in the footsteps of his uncle, Rev. Luke Bohr, OSB, serving as Prior of the monastery for ten years, and as keeper of Mass Intentions. Many faithful in the parishes of the area benefited from the sacramental help provided by Fr. Kenneth in his priestly duties, as well as in his role as a spiritual director. Fr. Kenneth was an ardent Chicago Cubs fan, a person who never encountered a jigsaw puzzle he could not finish. He was a loving family member to his numerous relatives, near and far. In his last years, Father Kenneth experienced several debilitating physical ailments, leading to a lack of mobility and confinement, first to the infirmary at the Abbey, and in more recent years, to St. Patrick’s Residence in Naperville, where he was deeply loved. He maintained a keen mind, a firm faith, and sense of humor through it all. Father Kenneth was preceded in death by his parents, two sisters (Doris and Sister Merina, SSSF) and five of his brothers (Robert, Harry, Gerald, Ray and James). He is survived by his brother Richard, many nieces and nephews, and his brother monks. The body of Father Kenneth will be received at Marmion Abbey’s St. Augustine of Canterbury Church at 4:00 pm on Friday, August 15. Visitation will follow until 8:00 pm, with a Vigil Service at 7:00 pm. A Mass of Christian Burial will take place at Marmion Abbey on Saturday, August 16, at 10:30 am. Visitation will continue the hour before the start of the liturgy. Burial will follow at Marmion Abbey Cemetery. Funeral arrangements were entrusted to The Daleiden Mortuary, 220 N. Lake St., Aurora, IL. 60506. Please remember to sign the virtual guest book and leave condolences for Fr. Kenneth's family.

Fr. Kenneth Theisen, OSB

November 1, 1941 - August 8, 2025