boy names starting with OBoy names starting with O are riding high, with Oliver at the heights of popularity, and Owen not too far behind.

But a surprising number of rare O names for boys exist, too. Surnames like Orson and Ogden, imports like Octavio and Oleg, and mythological names from multiple traditions also begin with this bright and energetic letter.

O ranks 17th out of the 26 letters of the alphabet in terms of popularity, putting it well behind A and E, but ahead of I and U.

Top Ten favorite Oliver fuels some of that rank. Over 15,000 boys received the name in 2022. It’s wildly popular elsewhere in the English-speaking world, as well as throughout Europe, ranking in the Top 50 – or better – from Norway to Hungary to Spain, to name just a few.

Lately, cozy-cool nickname Ozzy has been a rising favor, whether it’s short for Oscar or standing on its own.

TOP 1000 BOY NAMES STARTING WITH O

OLIVER (#3)

A chart-topping favorite across much of the world, Oliver feels traditional, if not quite classic. It’s a playful name, but a sophisticated one, too. With Germanic roots and plenty of historical notables, Oliver is rooted in the past – but has never been more popular. Sister name Olivia currently ranks #1 in the US.

OWEN (#18)

A Welsh name – and sometimes Irish, too – Owen has become a go-to for parents in our era of boy names ending with n. The spelling Owain is far more rare.

OSCAR (#201)

Borrowed from Irish myth, Oscar blends a literary vibe (Wilde) with all the innocence of Sesame Street. It’s spelled Oskar in German, Polish, and Scandinavian languages.

OMAR (#241)

Most familiar as an Arabic name, Omar means flourishing. It appears in the Old Testament, too, a Hebrew name meaning speaker.

OTTO (#309)

A palindrome name, Otto has been worn by a handful of famous Germans. It feels traditional-ish, but also quirky-cool in the US today.

ODIN (#330)

A mythological possibility, we all know the Norse god Odin – father of Thor – thanks to the Avengers movies.

ORION (#331)

A constellation depicting a hunter from Greek myth, Orion is familiar to all stargazers.

ONYX (#355)

A gemstone found all over the world, Onyx is associated with its typical inky-black color.

OAKLEY (#394)

A cool and edgy surname name, Oakley brings to mind oak trees, but also the sunglasses company. It’s a white-hot unisex favorite.

OMARI (#536)

Likely a Swahili spin on Omar, though other origins are possible.

OCEAN (#604)

A nature name every bit as wearable as River.

OTIS (#613)

A buttoned-up version of Otto, originally in use as a surname.

OZZY (#620)

Once a heavy metal staple, Ozzy now feels casual, even cuddly. It could be short for surnames like Osborne and Osbourne, as well as rarities like Osric and Ozias, and, of course Oscar. But it’s just Ozzy that seems to be trending.

ORLANDO (#809)

A Florida place name, borrowed from poets of the Italian Renaissance, as well as Shakespeare’s As You Like It.

OSMAN (#972)

Way back around the year 1299, Osman I became founder of the Ottoman Empire. It’s rising in use among Arabic-speaking parents in the US, as well as in England and elsewhere.

OSIRIS (#977)

The Egyptian god of the underworld, a name at least as wearable as many other mythological gems.

RARE & UNUSUAL BOY NAMES BEGINNING WITH O

OAK

A tree name every bit as wearable as Rowan.

OAKES

A surname name that melds the best of Oakley and Wells into a first name with plenty of potential.

OBADIAH

Another Old Testament name fronted by the letter O, an alternative to Isaiah and Elijah.

OBERON

Shakespeare’s fairy king in A Midsummer Night’s Dream.

OBSIDIAN

A type of volcanic glass, another word for the color black, and an -ian ender. In other words, an alternative to Jasper, Onyx, and Julian, too.

OCTAVIAN

With baby boy names Julian and Adrian so in favor, why not ancient Octavian?

OCTAVIO

A romance-language take on ancient Octavius.

ODELL

Made famous by the NFL’s Odell Beckham, Jr., the name comes from an English place name.

ODYSSEUS

The much-traveled hero of Greek legend and Homer’s epic, The Odyssey. 

OGDEN

A place name-turned-surname, American poet Ogden Nash helps put this on the list of first-name possibilities.

OISIN

The name of a warrior from Irish legend, Oisin means little deer.

OLAF

A traditional Scandinavian name, Olaf has been worn by five kings of Norway, plus the snowman from Frozen. The spelling Olav is sometimes seen, too. It means “ancestor.”

OLEG

A Russian name meaning blessed, Oleg has never caught on in the US.

OLIN

A Scandi import, cousin to Olaf – and likely a little more accessible for Americans.

OLIVIER

The French form of Oliver, made famous by legendary actor Sir Laurence Olivier.

OLLE

Pronounced just like Ollie, Olle is traditional Swedish nickname for any name starting with Ol.

OLLIVANDER

It looks like an Oliver-Alexander smoosh. Ollivander would be a unique boy’s name, inspired by Garrick Ollivander, the wizard who makes wands in Diagon Alley in the Harry Potter books.

OMRI

An Old Testament name of a wicked king, Omri nonetheless feels ready for redemption now.

OREN

A Hebrew name meaning pine tree. Orin may be another spelling, or have different roots.

ORPHEUS

A tragic figure from Greek myth, Orpheus was a gifted musician who almost rescued his wife from the underworld. His story is told and re-told in opera and ballet, sculpture and literature. Romance language form Orfeo is familiar, too, especially thanks to some of those uses.

ORRAN

The Anglicized version of Odhran, the name of an Irish saint.

ORSON

Originally a Norman surname meaning bear cub, Orson brings to mind director Orson Welles and author Orson Scott Card.

OSLO

Place name with a cool, current sound.

ORVILLE

A name made famous by Orville Wright. Along with his brother Wilbur, he invented the first successful airplane in 1903.

OSWALD

A saintly name with Old English and Norse roots, Oswald is known to some as the name of Walt Disney’s first animated creation – a rabbit. The romance language Osvaldo is heard in Italian, Spanish, and Portuguese.

OSSIAN

Also spelled Oisin, this name stepped right out of Irish legend. It means “little deer.”

OTHELLO

A tragic figure from one of Shakespeare’s dramas, but also an o-ending name with a current sound.

OZIAS

Ozias is slightly more common than just-Oz, but in our age of Bo, is Oz any less wearable? It’s among the truly rare boy names beginning with O on this list.

What are your favorite boy names beginning with O?

First published February 8, 2021, this post was revised on October 18, 2021; November 28, 2022; and December 18, 2023.

boy names starting with O boy names starting with O

About Abby Sandel

Whether you're naming a baby, or just all about names, you've come to the right place! Appellation Mountain is a haven for lovers of obscure gems and enduring classics alike.

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9 Comments

  1. One of our sons has the middle name October. We weren’t brave enough to use it as a first name, but I really love it. The nickname Toby is cute. Could this be used on a boy?

  2. Big fan of Oz. It’s literary, has a wonderful meaning, and packs a one-syllable punch.

    I think a lot of Bible-readers stay away from Onan because he was wicked and executed by the Lord.

    Orville would be an amazing comeback moniker! If Millie, Otis, and Agatha work, why not Orville?

    Great list!

  3. If your looking for a short, biblical, O staring boys’ name what about Onan. The reason Onan is so underused (I believe at least) is because for a long time people believed that the biblical Onan subverted the natural order of things, now this was because in the Old testament Onan refused to sleep with his recently widowed sister in law (now his wife, law of his tribe). Now our ancestors inferred that the reason why Onan ‘spilled his seed outside the marriage bed’ was because he was gay, this belief was still very prevalent in Victorian times. The way most people think of the British public* (private) schools is a direct cause of the Anti Onanist Matthew Arnold treatise on how to ‘educate the Sons of Empire’, Arnold suggested a relatively harsh regime of Academics, religious observance (going to church/ Chapel at least once a day is still commonplace at most British public schools) and sport would discourage the young men at schools that subscribed to the regimen to not molest themselves (I.e self masturbate). Another (probable) anti Onanist was William K. Kellogg who suggested his clients (initially, then everyone) eat his (new fangled) Cornflakes to stop them from touching themselves

  4. How about Orpheus? Cool Greek mythological character and musician. Similar to Morpheus which may get a bump from the new Matrix movie coming out.

  5. Otto, Otis, Oscar, Orson, Oberon, Orion, Odin: all some of my absolute favorite boy names! Something about that soft O gives me soft + strong vibes — like a bear hug in name form. Great list!

  6. Our two boys have the middle names Obadiah and Ozias. Being Christians we loved the meaning of them both but thought the names were a little too oddball to use as firsts (Obadiah more so than Ozias, as something about it just felt too old-manlike to use on a baby. Ozias was a real toss up for first or middle place as it’s unusual but has a fairly modern vibe to it, but another name won out for first place). Since announcing their names we’ve had so many positive comments about the choice of middle names, as well as some cute nickname ideas based on these, so maybe we could have used them as firsts without any worry.

  7. I’ve been thinking of the name Oak recently – maybe more as a middle name though! Oak trees have a lot of significance to my family. And before he died, my grandfather gave each of his granddaughters a necklace with an oak tree charm on it.