O

Odile, Saint

Odilo of Cluny, Saint

Odo of Canterbury, Saint

Odo of Cluny, Saint

Óengus of Tallaght, Saint

Oliver Plunkett, Saint

Olympia the Deaconess, Saint

Omer, Saint

Onesimus, Saint

Onophrius, Saint

Opportuna, Saint

Optatus of Milevis, Saint

Osanna of Mantua, Blessed

Osgyth, Saint

Osmund of Salisbury, Saint

Oswald of Northumbria, Saint

Oswald of Worcester, Saint

Oswin, Saint

Othmar, Saint

Otto of Bamberg, Saint