Baby names starting with O
30 names beginning with O, each with an editorial meaning and origin note and its real popularity rank from the 2025 U.S. Social Security Administration data. Rank is U.S.-only and reflects how records are grouped in that source.
- Oakland from the California city, named for its oak groves; the English words 'oak' + 'land'
- Oaklee modern American coinage, the English word 'oak' with the -lee ending; compare the surname Oakley = 'oak clearing'
- Oakleigh modern respelling of Oakley, an English surname from a place name = 'oak clearing', from Old English 'ac' + 'leah'
- Oakley transferred surname from English place names, Old English 'ac' = oak + 'leah' = wood, clearing
- Oaklyn modern American coinage, the English word 'oak' with the popular -lyn suffix
- Oaklynn modern American coinage joining the word oak (Old English 'ac', the tree) to the popular suffix -lynn
- Ocean from the English word, Greek Okeanos, the great river the Greeks believed encircled the world
- Octavia feminine of the Roman family name Octavius, from 'octavus' = eighth
- Octavio Spanish form of Octavius, from Latin 'octavus' = eighth
- Odessa from the Ukrainian Black Sea city, named in 1795 after the ancient Greek colony Odessos
- Odin from Old Norse Odinn, chief of the Norse gods, from 'odr' = fury, inspiration, poetry
- Olive from the tree and its fruit, Latin 'oliva'; the branch is an old emblem of peace
- Oliver from the Old French Olivier, borne by Charlemagne's companion in the Song of Roland; either from Latin 'oliva' = olive tree, or a French reworking of the Norse Aleifr (Olaf); root debated
- Olivia feminine of Oliver, or taken straight from Latin 'oliva' = olive, whose branch has stood for peace since antiquity; brought into English use by Shakespeare's Twelfth Night (c. 1602)
- Ollie diminutive of Oliver, from the Norman name Olivier; either from Latin 'oliva' = olive tree, or reshaped from a Germanic name; root debated
- Omar Arabic Umar, from a root meaning to live long, to thrive; a separate Hebrew Omar appears in Genesis
- Omari Swahili form of the Arabic Umar, from a root meaning to live long, to thrive
- Onyx gemstone name, from Greek 'onux' = claw, fingernail; the banded stone was thought to resemble a fingernail
- Opal gemstone name, from Latin 'opalus', ultimately from Sanskrit 'upala' = stone, precious stone
- Ophelia probably coined by the Italian poet Sannazaro in the 15th century from Greek 'ophelos' = help, benefit; taken up by Shakespeare for Hamlet
- Orion the hunter of Greek myth and the constellation named for him; the name is pre-Greek and its sense is uncertain
- Oscar either from Old Irish 'os' = deer + 'cara' = friend, or from Old English Osgar, 'os' = god + 'gar' = spear; spread across Europe by Macpherson's Ossian poems
- Osiris Greek form of the Egyptian god name Wsir (Usir), lord of the dead and of resurrection; the Egyptian root is disputed
- Osman Turkish form of the Arabic Uthman, the name of a bird; borne by Osman I, founder of the Ottoman dynasty
- Otis transferred surname from the medieval given name Ode or Odo, from Germanic 'od' = wealth, fortune
- Otto Germanic, from 'od' = wealth, fortune, inheritance
- Owen Welsh Owain, most often traced to Latin Eugenius (Greek 'eugenes' = well-born), though a native Celtic root meaning 'born of the yew' is also argued; root debated
- Ozias Greek form of the Hebrew Uzziyah = 'Yahweh is my strength'
- Oziel Spanish form of Hebrew Uzziel, from 'oz' = strength + 'el' = God; 'God is my strength'
- Ozzy diminutive of Oswald or Osbourne, from the Old English element 'os' = god
Only names carrying a meaning note are listed here. Popularity-only records exist for many more spellings and are reachable through the full directory search.
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