A priest of the Archdiocese of Tororo – Uganda, Fr. Deo was ordained in 1998 after his seminary studies at Notre Dame Seminary.
He then served for seven years as Secretary to his bishop and Chancellor of the diocese. During that time he also served for four years as Vocations director and Master of Ceremonies of the diocese and three years as Pastor of Queen of Peace Parish in Kachongha.
After his studies in Sacramental Theology in Rome, where he earned a Doctorate in Sacred Theology, Fr. Deo began serving on the faculty of Notre Dame Seminary in 2009. At NDS Fr. Deo serves as the Vice-Rector, Director of Human Formation, a Professor of Sacramental Theology and Liturgy and a Formation Adviser.