Names borne by several saints
Names borne by a single saint
- Obdulio · Luis Navarro
- Octavio · Octavio Ortiz Arrieta
- Oda · Blessed Oda
- Oderic · Blessed Oderic of Pordenone
- Odette · Odette Vidal de Oliveira
- Odile · Saint Odile of Hohenbourg
- Odilon · Saint Odilo of Cluny
- Odoardo · Odoardo Focherini
- Odolric · Saint Odolric
- Olallo · José Olallo Valdés
- Olinto · Olinto Marella
- Oliva · Maria Oliva Bonaldo
- Olympia · Saint Olympias (Olympias) of Constantinople
- Olympias · Saint Olympias (Olympias) of Constantinople
- Omer · Saint Omer (Audomarus)
- Onuphrius · Saint Onuphrius (Anchorite)
- Opportune · Saint Opportune
- Optatus · Saint Optatus of Milevis
- Orestes · Oreste Fontanella
- Origen · Origen of Alexandria
- Oringa · Blessed Oringa (Christina of the Holy Cross)
- Ortaire · Saint Ortaire of Landelle
- Oscar · Oscar Gattiani
- Otrude · Saint Rotrude (Otrude)
- Ottorino · Ottorino Zanon
- Oudard · Blessed Odo (Oudard)
- Ouen · Saint Ouen (Dadon)
- Outrille · Saint Austregisilus (Outrille)
- Oyend · Saint Eugendus (Oyend)
- Ozanne · Saint Ozanna
Other saints — O
Records whose name starts with O, without a referenced derived first name.