Here’s every “O” name on my list 
[name_m]Oak[/name_m]
[name_f][/name_f][name_m]Orrin[/name_m]
[name_f][/name_f][name_f]Opa[/name_f]
[name_f][/name_f][name_f]Ora[/name_f]
[name_f][/name_f][name_f]Orlagh[/name_f] / [name_f]Orla[/name_f]
[name_f][/name_f][name_f]Oni[/name_f]
[name_f][/name_f][name_f]Osla[/name_f]
[name_f][/name_f][name_m]Omri[/name_m]
[name_f][/name_f][name_f]Opal[/name_f]
[name_f][/name_f][name_f]Olwen[/name_f]
[name_f][/name_f][name_f]Odette[/name_f]
[name_f][/name_f][name_f]Olive[/name_f]
[name_f][/name_f][name_m]Ozzy[/name_m]
[name_f][/name_f][name_f]Olea[/name_f]
[name_f][/name_f][name_m]Ocean[/name_m] / [name_f]Oceana[/name_f]
[name_f][/name_f][name_f]Olinda[/name_f]
[name_f][/name_f][name_f]Ophelia[/name_f]
[name_f][/name_f][name_f]Othelia[/name_f]
[name_f][/name_f][name_f]Odelia[/name_f]
[name_f][/name_f]Odelah
[name_f][/name_f][name_f]Olivet[/name_f]
[name_f][/name_f][name_f]Ophira[/name_f]
[name_f][/name_f][name_f]Odessa[/name_f]
[name_f][/name_f]Odeyah
[name_f][/name_f][name_f]Oriel[/name_f]