| Name | Anagram(s) |
|---|
| Oba | Abo, Bao, Boa |
| Obed | Bode |
| Obi | Iob |
| O'Brien | Breion, Brieon, Brione |
| Octavia | Vocatia |
| Oda | Aod |
| Odalis | Isolda |
| Ode | Deo, Doe |
| Oded | Eddo |
| Odel | D'Ole, Eldo |
| Odelia | Eladio, Elodia |
| Oden | Deon |
| Odeta | Tadeo |
| Odhrán | Rhonda |
| Ödi | Ido |
| Odila | Idola, Loida |
| Odilon | Olindo |
| Odin | Dino, Dion |
| Odoacer | Odoacre |
| Odoacre | Odoacer |
| Odra | Dora, Orad |
| Odran | Andor, Andro, Donar, Doran, Radon, Rodan, Ronda |
| Ofir | Ofri |
| Ofra | Afro |
| Ofri | Ofir |
| Ohad | Aodh, Doha, Hoad |
| Oihana | Ainhoa |
| Oileus | Louise |
| Oina | Aino, Ioan, Iona |
| Oisín | Soini |
| Okan | Noak |
| Ola | Alo, Lao |
| Olaf | Álǫf |
| Olav | Lova |
| Olavi | Oliva, Viola |
| Ole | Elo, Leo |
| Olek | Kole, Loek, Loke |
| Oleksandr | Androkles |
| Oleksandra | Aleksandro |
| Olen | Elon, Leno, Leon, Lone, Noel, Nole |
| Olena | Elona, Enola, Leona, Loane, Noela |
| Olenia | Elonia, Eniola, Enolia, Eolian, Ionela, Leonia, Noelia |
| Oles | Leoš, Loes, Sole |
| Oleta | Leota |
| Olev | Elov, Love, Olve |
| Olga | Galo, Gola |
| Olid | Doli, Idol, Ildó |
| Olin | Lino, Lion, Loni, Nilo, Noli |
| Olina | Aniol, Ilona |
| Olinda | Danilo, Dolina, Donila, Ladino |
| Olindo | Odilon |
| Oline | Ionel |
| Oliva | Olavi, Viola |
| Olive | Elvio, Lovie, Viole |
| Oliventa | Violante, Violenta |
| Oliver | Viorel |
| Olivera | Valerio, Valorie, Viorela |
| Olivette | Violette |
| Olivia | Ivailo |
| Olja | Jalo, Jola |
| Olli | Lilo |
| Ollie | Lelio |
| Olson | Solon |
| Olve | Elov, Love, Olev |
| Olwen | Nowel |
| Olyvia | Ivaylo |
| Om | Mo |
| Oma | Mao, Moa |
| Oman | Amon, Mona, Noam |
| Omar | Amor, Armo, Maor, Maro, Mora, Roma |
| Omari | Ioram, Maori, Mario, Moira, Raimo |
| Omer | Ermo, Orem, Remo, Rome |
| Omid | Dimo |
| Omran | Moran, Morna, Norma, Ramon, Roman |
| Omri | Miro, Romi |
| Omura | Amour, Mauro, Oumar |
| Omusa | Masou, Osamu, Souma, Suoma |
| Ona | Aon, Nao, Noa |
| Onager | Agenor, Gaenor, Genaro, Nagore, Orange |
| Onatah | Onatha |
| Onatha | Onatah |
| Ondina | Andoni |
| Ondine | Dionne, Donnie |
| Ondrej | Jorden |
| Oneida | Idonea |
| O'Neill | Leolin, Lionel, Niello, Nollie |
| Onesa | Aeson, Eason, Osane, Saone, Seona |
| Ongar | Agron, Garon, Goran, Nagor |
| Oni | Ino, Ion |
| Onida | Adino, Danio, Doina |
| Onie | Eino, Eoin, Ione |
| Onisim | Simion, Simoni |
| Onni | Nino |
| Onóra | Noora |
| Onur | Nour |
| Onyx | Xyno |
| Oona | Nooa |
| Opal | Lapo, Paol, Pola |
| Opala | Paola |
| Ophra | Harpo, Oprah, Orpah, Orpha |
| Oprah | Harpo, Ophra, Orpah, Orpha |
| Orad | Dora, Odra |
| Oral | Arlo, Lora, Orla, Rola |
| Oralee | Eleora |
| Orali | Alroi, Liora |
| Oralie | Elario, Eliora |
| Oran | Arno, Aron, Nora, Orna, Roan, Rona |
| Orange | Agenor, Gaenor, Genaro, Nagore, Onager |
| Orb | Bor, Rob |
| Orbán | Baron, Boran, Borna |
| Orbit | Tibor |
| Orca | Caro, Cora |
| Orcus | Corus |
| Orel | Erol, Leor, Lore, Orle, Roel |
| Orem | Ermo, Omer, Remo, Rome |
| Oren | Erno, Nero, Reno |
| Orenda | Dorean |
| Organa | Agrona, Angora, Aragon |
| Orhan | Nahor, Norah, Ornah, Rhona, Rohan |
| Ori | Iro, Rio, Roi |
| Orin | Nori, Rino, Roni |
| Orinda | Darion, Dorian, Dorina, Iordan, Rodina |
| Oris | Rišo, Róis, Siôr, Sori |
| Orison | Orsino |
| Orit | Tori |
| Orjan | Jaron, Jöran, Ronja |
| Orji | Jiro, Jori |
| Orla | Arlo, Lora, Oral, Rola |
| Órlaith | Lothair |
| Orlan | Lorna, Rolan |
| Orland | Arnold, Landor, Lardon, Loránd, Roland, Roldán, Ronald |
| Orlanda | Alondra, Arnaldo, Ronalda |
| Orlando | Arnoldo, Rolando, Rolonda, Ronaldo, Ronolda |
| Orle | Erol, Leor, Lore, Orel, Roel |
| Orlena | Elanor, Elnora, Lenora, Lorena |
| Orlenda | Elondra, Ladrone, Leandro, Leonard, Leondra, Roeland, Rolande |
| Orli | Lior, Lori |
| Orlin | Liron, Lorin, Ronil |
| Orlinda | Lorinda, Rinaldo |
| Orlo | Rolo |
| Orly | Lory, Roly |
| Ormond | Modron |
| Orna | Arno, Aron, Nora, Oran, Roan, Rona |
| Ornah | Nahor, Norah, Orhan, Rhona, Rohan |
| Ornat | Antor, Arton, Taron, Toran |
| Orpah | Harpo, Ophra, Oprah, Orpha |
| Orpha | Harpo, Ophra, Oprah, Orpah |
| Orsina | Arsino, Rosina, Sirona, Sorina |
| Orsino | Orison |
| Orso | Roos |
| Osama | Masao, Samoa |
| Osamu | Masou, Omusa, Souma, Suoma |
| Osane | Aeson, Eason, Onesa, Saone, Seona |
| Osbeorn | Osborne |
| Osbert | Strobe |
| Osborne | Osbeorn |
| Osgar | Argos |
| Oshea | Hosea |
| Oskar | Rokas |
| Oskari | Ikaros |
| Osku | Usko |
| Osman | Mason, Sonam |
| Osmund | Domnus |
| Östen | Seton, Stone |
| Oswald | Waldos |
| Ota | Tao |
| Otar | Arto, Rota, Taro, Tora |
| Otilia | Atilio |
| Otmar | Morta, Tarmo |
| Ottilia | Attilio |
| Ottis | Titos, Totsi |
| Oumar | Amour, Mauro, Omura |
| Oved | Dove |
| Owain | Iwona |
| Oxana | Xoana |
| Oya | Ayo, Yao |
| Öykü | Kyou, Yuko |
| Ozan | Anzo, Zona |
| Ozi | Zoi |
| Ozias | Zosia |