1959 -- Born in Bethesda, Maryland the son of Gillis & Shirley Mancuso
June 1978 -- Graduated from Fredonia High School, Fredonia, NY
1978-1981 -- Served in the United States Navy as an enlisted man.
1987-1991 -- Attended Wadhams Hall Seminary-College, Ogdensburg, NY -- graduating in 1991 with a Bachelor of Arts degree
1991-1995 -- Attended Christ the King Seminary, East Aurora, NY -- graduating in 1995 with a Master of Divinity Degree
June 25, 1995 -- Ordained as a Transitional Deacon by the Most Rev. Henry J. Mansell, Bishop of Buffalo - Served as a Deacon at All Saints Parish, Buffalo, NY
May 4, 1996 -- Ordained a Priest of the Roman Catholic Diocese of Buffalo, New York by the Most Rev. Henry J. Mansell, Bishop of Buffalo
May 4, 1996 - July 31, 1997 -- Served as Parochial Vicar at All Saints Parish, Buffalo, NY
Aug. 1, 1997 - Dec. 13, 2002 -- Served as the Parochial Vicar of Fourteen Holy Helpers Parish, in West Seneca, NY
April 2000 -- Received Bi-ritual Faculties from the Holy See to serve at the Divine Liturgy and the Sacraments in the Ukrainian Byzantine Catholic Church
Dec. 14, 2002 - Feb. 21, 2006 -- Served as the Administratorof St. Mary's Parish in Belmont, NY; St. Joseph's Parish in Scio, NY; and Sacred Heart Parish, Angelica, NY
Fall of 2005 - Present -- Was appointed as Spiritual Assistant to the Our Lady of Grace Group (Cuba, NY) of the Secular Order of Discalced Carmelites (OCDS); in which he received the Scapular taking the name of Father Dionysius of the Most Blessed Sacrament. Fr. Dennis made Definitive Promises in 2012.
Feb. 22, 2006 - July 13, 2007 -- Was appointed as Pastor of St. Mary's Parish in Belmont, NY; St. Joseph's Parish in Scio, NY; and Sacred Heart Parish, Angelica, NY by the Most Rev. Edward U. Kmiec, Bishop of Buffalo
Aug. 7, 2006 - July 13, 2007 -- In addition to being Pastor of St. Mary's Parish in Belmont, NY; St. Joseph's Parish in Scio, NY; and Sacred Heart Parish, Angelica, NY. The Most Rev. Edward U. Kmiec, Bishop of Buffalo, appointed him as Administrator of St. Patrick's Parish, Belfast, NY
July 14, 2007 - October 23, 2013 -- With the merging of the parishes in Belmont, Scio, and Angelica into Holy Family of Jesus, Mary, and Joseph in Belmont, NY. Fr. Dennis was appointed by the Most Rev. Edward U. Kmiec, Bishop of Buffalo, as the Pastor of St. Patrick's Parish, Belfast, NY and St. Patrick's Parish, Fillmore, NYwith diocesan mandate to initiate a Catholic Campus Ministry to Houghton College, in Houghton, NY. September 1, 2011 - October 23, 2013 --In addition to being the Pastorof St. Patrick's Parish, Belfast, NY and St. Patrick's Parish, Fillmore, NY, Fr. Dennis was appointed by the Most. Rev. Edward U. Kmiec, Bishop of Buffalo, as the Administrator of Our Lady of the Angels Parish in Cuba, NY.
March 1, 2012 - March 24, 2012 --In addition to being the Pastorof St. Patrick's Parish, Belfast, NY, St. Patrick's Parish, Fillmore, NY, and Administrator of Our Lady of the Angels, Cuba Fr. Dennis was appointed by the Most. Rev. Edward U. Kmiec, Bishop of Buffalo, as the Administrator of St. Marks Parish Rushford until its merger into St. Patrick's Parish on March 25, 2012. St. Mark remains as an Oratory of St. Patrick's in Belfast with one Mass a weekend from Memorial Day Weekend to Mid-September Annually.
October 24, 2013 - August 11, 2022 Fr. Dennis continued to served as Pastor of St. Patrick's Parish in Fillmore, and St. Patrick's Parish in Belfast with St. Mark's Oratory, Rushford and Our Lady of the Angels Parish in Cuba.
August 15, 2017 - Present Fr. Dennis serves as Sacramental Priest to St. Mary of the Dormition Byzantine (Ruthenian) Catholic Chirch of Olean, NY.
August 12, 2022 - Present Fr. Dennis serves as Pastor of the Three Catholic Sisters of the Foothills Family of Parishes (Holy Name of Mary - Ellicottville; St. Philomena - Franklinville; and Our Lady of Peace - Salamanca).