Cool Names with a Strong O

Cool Names with a Strong O

Baby names that begin or end with the letter O have long been particularly cool, especially (though there are a few feminine selections) for boys. The most popular girl name in the US, Olivia, has a strong O beginning, as does its rising masculine counterpart, Oliver. Both names are extremely popular throughout the Western world.

Along with Olivia and Oliver, other cool names with a strong O in the US Top 250 include Arlo, Diego, Enzo, Leo, Mateo, Milo, Olive, and Theo. Names with multiple Os may be especially cool — such as Apollo, Oona, Otto, and Rocco.

The options for cool names starting or ending with O range far beyond those offered here, of course, especially considering the entire world of Latinate baby names out there, but this group should give you a pretty good start.

  1. Arlo
    • Origin:

      Irish or English
    • Meaning:

      "between two hills"
    • Description:

      Quirky cool Arlo is now well and truly back. Last year it broke into the US Top 200 boy names and consistently ranks among the most popular boy names on Nameberry.
  2. Olivia
    • Origin:

      Latin
    • Meaning:

      "olive tree"
    • Description:

      Olivia, a lovely Shakespearean name with an admirable balance of strength and femininity, is the Number 1 name for baby girls in the US and one of the top girls' names around the world.
  3. Milo
    • Origin:

      Latin and Old German
    • Meaning:

      "soldier or merciful"
    • Description:

      Milo is most commonly considered to be Germanic name derived from the Latin word miles, meaning "soldier." However, there is evidence to suggest it also may have independently spawned from the Slavic root milu, meaning "merciful." Milo predates brother name Miles, a variation that evolved when the name immigrated to the British Isles in the Middle Ages. Mylo is an alternate spelling.
  4. Oliver
    • Origin:

      Latin
    • Meaning:

      "olive tree or elf army"
    • Description:

      Oliver is an international star, ranking near the top of the charts in the US and throughout the English-speaking world, along with a host of European and Latin American countries, from Norway to Chile, Slovenia to Switzerland.
  5. Mateo
    • Origin:

      Spanish
    • Meaning:

      "gift of God"
    • Description:

      Mateo vaulted into the boys' Top 10 in 2023, ranking all the way up at Number 6. Counting Mateo and Teo along with Anglo equivalents Theodore and Theo make this by far the Number 1 boys' name in the US.
  6. Ophelia
    • Origin:

      Greek
    • Meaning:

      "help"
    • Description:

      Floral, elegant, and bold, Ophelia re-entered the US Top 1000 in 2015 after more than 50 years off the charts. It has risen more than 700 spots since then and shows no signs of slowing down. Now in the US Top 300, could Ophelia one day become the next Olivia or Amelia?
  7. Leo
    • Origin:

      Latin
    • Meaning:

      "lion"
    • Description:

      Leo is a strong-yet-friendly name that was common among the Romans, used for thirteen popes, and is now at its highest point ever in the US thanks in part to Leonardo "Leo" DiCaprio.
  8. Oscar
    • Origin:

      English or Irish
    • Meaning:

      "God spear, or deer-lover or champion warrior"
    • Description:

      Oscar is one of the most stylish Old Man Names of our era. While it's softened slightly in popularity over the past 20 years, that may be considered a very good thing.
  9. Hugo
    • Origin:

      Latinized form of Hugh
    • Meaning:

      "mind, intellect"
    • Description:

      Hugo, the Latin form of Hugh, has more heft and energy than the original -- and of course we love names that end (or begin, for that matter) with an o. This one is especially appealing because it's backed up by lots of solid history and European style.
  10. Elio
    • Origin:

      Italian, Spanish
    • Meaning:

      "sun"
    • Description:

      Elio is a sunny and spirited Italian and Spanish name that makes a great crossover prospect, which could catch on as Enzo has. Elio is also currently popular in France, ranking in the Top 250.
  11. Theo
    • Origin:

      Diminutive of Theodore
    • Meaning:

      "gift of God"
    • Description:

      See the popularity graph below for the name Theo? It's been heading straight uphill since 2010, when it hopped back onto the Top 1000 after a 60+ year absence.
  12. Otto
    • Origin:

      German
    • Meaning:

      "wealthy"
    • Description:

      Otto is cool again. Long a quintessential Old Man Name, Otto has been promoted to trending darling of adventurous baby namers.
  13. Owen
    • Origin:

      Welsh
    • Meaning:

      "young warrior; well-born"
    • Description:

      Owen, a resonant Celtic name, has ranked among the Top 100 boys' names in the US for 20 years and is now at its highest point ever.
  14. Orion
    • Origin:

      Greek
    • Meaning:

      "boundary, limit"
    • Description:

      Orion is a rising star, with both mythical and celestial overtones.
  15. Cleo
    • Origin:

      Greek
    • Meaning:

      "glory"
    • Description:

      Cleo, one of the few girls' names to boast the cool-yet-lively o ending, is of course short for Cleopatra, the name of one of the most powerful women in history.
  16. Otis
    • Origin:

      Variation of Otto, German
    • Meaning:

      "wealthy"
    • Description:

      Otis has real appeal for parents attracted to its catchy O initial and combination of strength and spunk. The appealing hero of the British TV show Sex Education has done much to propel Otis into the forefront of cool names.
  17. Ottilie
    • Origin:

      German, French
    • Meaning:

      "prosperous in battle"
    • Description:

      Ottilie is trending in the UK, where the pronounced T helps the name sound pretty and delicate, rather like Amelie and Elodie. Ottilie is less popular in the US, where many Americans pronounce it as a near-homonym for "oddly".
  18. Nico
    • Origin:

      Italian diminutive of Nicholas, Greek
    • Meaning:

      "people of victory"
    • Description:

      Nico is one of the great nickname names, full of charm, energy and effortless cool -- a neo Nick.
  19. Enzo
    • Origin:

      Italian variation of Henry, also diminutive of Vincenzo and Lorenzo
    • Description:

      Enzo originated as the Italian variation of Heinz, a German name derived from Heinrich, related to Henry. It has historically been used as a short form for Italian names such as Vincenzo and Lorenzo. The most famous bearer of the name is Enzo Ferrari, founder of the luxury sports car brand.
  20. Ozias
    • Origin:

      Greek
    • Meaning:

      "salvation"
    • Description:

      Everyone says they want an unusual name — well, if you truly do, this is one with Biblical cred that fits the bill, with the added attraction of the user-friendly nickname of Oz or Ozzie. Ozias is the name of several minor figures in the Bible. Osias is another spelling.