O is one of the rarest letters to begin a name with, which immediately makes O girl names distinctive. Names starting with O tend to have a warmth and openness to them, that round vowel at the start creating a welcoming, resonant quality. The range covers ancient mythology (Oya, Oshun, Ops), Celtic tradition (Orla, Órlaith, Onagh), soft and literary names (Ottoline, Olympia), Scandinavian names (Odin’s feminine counterparts, Oddny), and genuinely rare finds that almost no one has encountered before. Here is the full guide.
Table of Contents
Classic O Girl Names
Olivia
Latin, from the olive tree, associated with peace and wisdom in Mediterranean tradition. Olivia has been the most popular girl name in England and Wales for multiple consecutive years. If you want an O name that is universally recognised and warmly received, Olivia is the peak of that particular category.
Octavia
Latin, meaning “eighth.” The feminine form of Octavius. Octavia was the noble sister of Emperor Augustus, a woman of considerable political skill and personal dignity in an era when those qualities were rarely acknowledged in women. As a name she is formal, classical and shortens to Tavia or Ottie.
Ophelia
Greek, possibly meaning “help” or “advantage.” Shakespeare’s Ophelia in Hamlet is one of the most poignant and unjustly abandoned figures in English literature. The Pre-Raphaelite painters made her image iconic. The name is beautiful, literary and carries a gentle tragedy that some parents find too heavy and others find entirely appropriate.
Olive
From the olive tree and the colour. Olive is shorter and warmer than Olivia, a more direct botanical name with a slightly retro, mid-century quality. It is experiencing a quiet but consistent revival.
Odette
French, a diminutive of Oda, from the Old German meaning “wealth” or “fortune.” Odette is the white swan queen in Tchaikovsky’s Swan Lake. As a given name she is elegant, French and carries a specific artistic beauty.
Orla
Irish, an anglicisation of Órlaith (OR-lah), meaning “golden princess” or “golden sovereign.” Orla is one of the most widely used Irish names in England and Scotland, where it is warm, recognisable and carries an Irish identity without the pronunciation challenges of many Gaelic names.
Pretty O Names for Girls
Olympia
Greek, meaning “from Olympus” or “of the divine assembly.” Olympia Dukakis gave the name wide recognition. Olympia carries a grandeur and a sense of the divine, and is rare enough in everyday use to feel remarkable.
Ottoline
A diminutive form of Otto, ultimately from Old German meaning “wealth.” Ottoline Morrell was one of the great literary hostesses of early twentieth-century Britain, a patron of the Bloomsbury Group. The name is warm, slightly eccentric, and entirely distinctive.
Oriana
Latin or Italian, meaning “golden” or “dawn.” Oriana is long, flowing and has the same golden quality as Aurelia without the same level of current use.
Ondine
(on-DEEN) French and Germanic, from the Latin unda, meaning “wave.” Ondine is a water sprite in Germanic mythology. As a name she is rare, romantic and carries the elemental quality of water in her sound.
Odalys
(oh-DAH-lees) Spanish, from the Old German Odal, meaning “homeland” or “inherited wealth.” Odalys is a name used in Spanish-speaking communities and is almost entirely unknown outside them, making it genuinely distinctive.
Ottavia
Italian form of Octavia. Ottavia has the warmth of the Italian vowels and is rarer than its Latin equivalent in English-speaking countries.
Strong O Names for Girls
Órlaith
(OR-lah or OR-lith) Irish, meaning “golden princess” or “golden sovereign.” Órlaith is the full Irish form of Orla. Several early Irish queens and princesses bore this name. It is more specifically Irish in identity than the anglicised Orla.
Oya
Yoruba, the goddess of wind, storms, lightning and change in the Yoruba tradition of West Africa, also venerated in the Candomblé and Santería traditions of Brazil and the Caribbean. Oya is a goddess of transformation and the transition between life and death. Short, powerful and carrying an extraordinary mythological tradition.
Oshun
(oh-SHOON) Yoruba, the goddess of love, rivers, fertility and beauty in the Yoruba tradition. Oshun is one of the most widely venerated orishas and her name is used in West African and diaspora naming traditions. Rarely encountered outside those communities.
Ops
Roman goddess of the harvest and abundance, wife of Saturn. Ops is so short and so rarely used as a given name that it qualifies as entirely undiscovered.
Oddny
(ODD-nee) Old Norse, meaning “point of the sword” or “new edge.” Oddny was a significant figure in Norse saga literature. Scandinavian, strong and almost entirely out of use as a modern given name.
Rare O Girl Names Worth Knowing
Ondine
Already noted. The water sprite.
Oddny
Already noted. Norse blade edge.
Onagh
(OH-nah) Irish, a variant of Úna, meaning “lamb” or possibly “unity.” Onagh is the fairy queen in Irish folklore, the wife of Fionn mac Cumhaill in some traditions. It is very rarely used as a modern given name even in Ireland.
Oisín
Technically a male name (the great Irish poet Oisín), but the female form Oisíne (OSH-een-eh) appears in older Irish naming traditions. Almost entirely unused in modern contexts.
Oenone
(ee-NOH-nee) Greek mythology, the nymph who loved Paris before he abandoned her for Helen of Troy. Her name means “wine woman” or possibly “she of the wine.” Tennyson wrote one of his most celebrated poems about her. Rare, classical and carrying a story of abandonment and loss.
Oscara
The feminine form of Oscar, from the Irish os (deer) and cara (friend), meaning “friend of deer” or “god’s spear” in Old Norse. Oscara is almost never used as a given name and is genuinely extraordinary.
O Girl Names Inspired by Nature
Olive
Already noted. The peace tree.
Oak
From the tree, the symbol of strength and longevity in British tradition. Oak is almost never used as a given name and carries an enormous cultural weight in British landscape history.
Ochre
From the natural pigment, a warm yellow-brown colour made from iron-rich clay. Ochre as a colour name sits at the unusual end of the spectrum.
Opal
The iridescent gemstone. Opal is a gem name in the tradition of Pearl and Amber, warm and slightly vintage. It carries the fire of the stone’s shifting colours in its meaning.
Otter
From the semi-aquatic mammal. Otter is used very occasionally as a given name in nature-naming traditions. Rare, warm and entirely distinctive.
Orchid
From the tropical flower. Orchid as a given name is rarely used and carries a botanical exoticism.
O Girl Names From Mythology and Legend
Ops
Already noted. Roman abundance goddess.
Oya
Already noted. Yoruba storm goddess.
Oshun
Already noted. Yoruba love goddess.
Oenone
Already noted. The abandoned Greek nymph.
Ondine
Already noted. The Germanic water sprite.
Ostara
(oh-STAR-ah) Germanic goddess of spring and dawn, from whom the word Easter derives. Ostara is the goddess of the spring equinox and new beginnings. As a given name she is rare, seasonal and carries the warmth of the returning year.
Ops
Already noted.
Short O Girl Names
- Orla — Already noted. Irish golden princess.
- Opal — Already noted. Iridescent gem.
- Oya — Already noted. Yoruba storm goddess.
- Olive — Already noted. Peace tree.
- Ona — Lithuanian, a form of Anna. Short and warm.
- Ode — From the Greek poetic form. Rarely used as a name.
- Ora — Hebrew, meaning “light.” Short, clean and international.
O Girl Names by Origin
Irish and Celtic
Orla, Órlaith, Onagh, Oscara (Irish-Norse)
Greek and Classical
Olivia, Octavia, Ophelia, Oenone, Ops (Roman), Ostara (Germanic)
French and Germanic
Odette, Ottoline, Ondine, Oddny (Norse)
Italian
Ottavia, Oriana
Spanish
Odalys
Yoruba and West African
Oya, Oshun
Nature-rooted
Olive, Oak, Opal, Orchid, Ochre, Otter
Frequently Asked Questions About O Girl Names
What are the most popular O girl names?
Olivia is the most popular girl name in England and Wales and has been for several years. Orla and Olive are the next most widely used O names in the UK.
What are rare O girl names?
Oenone, Ondine, Oscara, Oddny, Onagh and Ostara are among the most genuinely uncommon O girl names with proper historical or mythological roots.
What middle names work with O girl names?
Long O names (Octavia, Olympia, Ophelia) suit short middles: Octavia Rose, Ophelia Faye. Short O names (Orla, Oya, Ora) work with longer middles: Orla Celestine, Oya Marguerite.
Final Thoughts
O girl names carry an intrinsic rarity because the letter itself is used so infrequently at the start of names. Even the most common O name, Olivia, sits in a category where the company is thin. For parents who want something that begins with a vowel but feels less crowded than A or E names, O offers real possibility, from the classical grandeur of Octavia and Ophelia to the Yoruba power of Oya and Oshun to the Welsh sovereignty of Órlaith.