Odart (I) derives from Old High German root ot and Old Saxon od (riches, wealth), and Old High German hart and Old Saxon hard (strong, hard). This name is also Medieval French, Medieval Scottish, and archaic Estonian.
Odelschalk (I) derives from Old High German root uodal (homestead, heritage) and Old Saxon skalk and Old High German scalh, scalc (servant). This name is also Medieval German.
Oderisi (I) derives from Latin name Oderisius, which is of uncertain etymology.
Odrich (I) derives from Old High German root ot and Old Saxon od (riches, wealth), and Old High German rih (ruler). This name is also Medieval French.
Offredo, Offrido (I) is a form of the Ancient Germanic name Autfrid, derived from Germanic root auda (property, wealth) and Old High German fridu (peace), or Ancient Germanic name Hohfrid, derived from Old High German roots hoh (high) and fridu. It may also have been a nickname for names ending in -offredo; e.g., Loffredo, Goffredo, Roffredo.
Omobono (I) means “good man.”
Obedienta (I) means “obedient.”
Odierna (I) is a form of Odierne, which is turn is an Old French form of an Ancient Germanic name possibly derived from roots od (riches, fortune, wealth) and gern (desiring, eager; gairns in Gothic). The Medieval French form, Hodierna, was possibly chosen because of the Latin word hodierna (existing now, present, of today).
Onesta (I) comes from the adjective onesta (sincere, honest) or the noun onestà (honesty).
Orelia (T) is a form of Aurelia (golden, gilded).