Phoenix Diocese Phoenix The Roman Catholic Diocese of Phoenix is committed to helping the faithful encounter the living Christ through conversion, communion and solidarity. Led by the Most Rev. Thomas J. Olmsted, more than 1.1 million Catholics make this diverse, vibrant and faith-filled diocese their home. Users who are followed by Phoenix Diocese FOCUS Fr-John L. Greb Fr-John Greb frmcguire Thaddeus McGuire Scottsdale bulldogCatholic Father Mike Schmitz Duluth, MN