Boy Names Ending in O: Bold, High Energy Choices

We love boy names ending in o.

Once rare – at least for native English speakers – they’ve gone mainstream. From king of the jungle Leo to romance language staple Diego to modern possibilities like Cairo, plenty of o-enders dot the US Top 1000, in a style to suit every namer.

Of course, rarities exist beyond the Top 1000. Our openness to boy names ending in o means that some of these could wear very well, indeed.

It feels like part of a bigger trend, a sea change in how we name our sons. Vowel endings once were rare, but now our most popular names include Noah and Elijah, Levi and Eli.

Whether you prefer to stick to mainstream favorites or are looking for something really daring, some of the boy names ending in o will almost certainly appeal to you.

FAMILIAR FAVORITES

ALEJANDRO, ALESSANDRO

Alex names have had a good run in the last few decades, so no surprise that Alejandro is popular, too. It’s the Spanish form. Meanwhile, Italian Alessandro ranks much lower on the list, but also benefits from the o-ending sound.

ANGELO

It’s never reached the heights that feminine form Angela has enjoyed, but Angelo is a familiar O-ending option.

ANTONIO

Actors and athletes have made this romance language form of classic Anthony broadly familiar, and very wearable.

ARLO

Arlo is an up-and-comer, likely to join Milo and Leo near the top of the charts soon. It carries a certain indie spirit thanks to folk singer Arlo Guthrie. And there’s a Disney-Pixar connection, too.

ARTURO

Of Spanish and Italian origin, Arturo adds some romance to traditional Arthur.

BEAU, BO

Beau means handsome in French, and you might hear it used to refer to a boyfriend. Bo might have Swedish roots – or Chinese! And longer forms of both spellings abound, from modern Bowen to gentlemanly Beauregard.

DIEGO, TIAGO, THIAGO

Speaking of James, Diego is another Spanish form. (Drop the San from Santiago, and you can almost hear it.) We all recognize it, thanks to San Diego, artist Diego Rivera, and Dora’s cousin. Thiago and Tiago belong to the same family, with Thiago ranking in the US Top 100.

ELIO

A fast-rising choice boosted by a smooth sound and an upcoming Pixar movie.

EMILIO, EMILIANO

Em- names have long topped the charts for girls. Emilio and Emiliano offer the same sound for our sons, but with a romance language spin.

ENZO, LORENZO, RENZO

Jersey Shore alum Nicole Polizzi named her firstborn Lorenzo Dominic in 2012. The reality star’s choice helped this romance language form of Lawrence climb the charts. Nickname Enzo feels every bit as stylish, and works well as a stand-alone name. Renzo splits Lorenzo in just a slightly different place.

HUGO

Hugo has been big in the UK, as well as Sweden, France, and Spain in recent years. It’s a true culture-spanning choice with a great meaning: heart, mind, or intellect.

JOE

Does good ol’ Joe belong on this list? We consider Joseph among the most classic of boy names. And while just Joe (and Joey) regularly appear in the US Top 1000, we don’t necessarily think of them as separate names. And yet, Joe feels friendly and approachable. It’s an upbeat name, one that I trust to fix my car, do my taxes, or care for my children.

LEO, LEONARDO

The lion rules the jungle, and Leo comes up near the top of the boy names ending in o list. So do lots of longer Leo names, including Leonardo. Hollywood A-Lister Leonardo DiCaprio put his long, romantic first name on our radar. Long before he boarded The Titanic, the name belonged to the legendary Leonardo da Vinci … and his Ninja Turtle namesake.

MATEO, MATTEO

New Testament Matthew is considered a classic. Romance language versions Mateo and Matteo feel extra energetic.

MILO, MYLO

Back in the 1980s, Milo felt edgy and obscure. Want proof? Punk band the Descendants were fronted by Milo Aukerman, and their album Milo Goes to College is a classic of the genre. Then we all fell in love with Miles, plus lots of boy names ending in o. Now Milo sounds like the (little) boy next door again.

NICO, NIKO

Unisex Nico belongs to the Nick name family, one of the most vibrant and modern of the group.

OTTO

A Germanic name that feels antique and quirky-cool.

SANTIAGO

Santiago means Saint James in Spanish. Confusing, right? Remember that James and Jacob share the same roots. In Biblical Latin, the name was Iacobus … which became Iago in Spanish. It’s wildly popular across the Spanish-speaking world right now, including in the US.

THEO

More parents prefer Theodore in full, but Theo isn’t too far behind. There are plenty of good reasons to skip the formal name, so no surprise o-ending Theo is trending. The meaning, “gift of God” is appealing to many, too.

RARE & SURPRISING BOY NAMES ENDING IN O

AERO, EERO

Aero refers to flight – think aeronautics and aerospace. Eero is the Finnish form of Eric. Neither is often heard as a given name in the US, but they could work.

ALBERTO

A Romance language spin on Albert.

ALDO

Brad Pitt made Aldo a tough guy name in the 2009’s Inglorious Basterds. Despite the ‘o’ ending, this name is actually falling in use.

ALONSO, ALONZO

Any Doctor Who fans out there? The Tenth doctor, David Tennant, famously cried “Allons-y, Alonzo” in an episode. That translates to “Let’s go, Alonzo!” But most parents are probably thinking of figures like basketball great Alonzo Mourning. Both spellings are from Alfonso; removing the ‘f’ modernizes the name nicely.

ALVARO

Take the Old Norse Alvar, add an ‘o’ and you’ll arrive at the Italian and Spanish Alvaro Verdi used it in an opera, based on a Spanish drama. It’s a globe-trotting name benefiting from the ‘o’ and the ‘v’ sounds.

AMADEO

The Latin origin Amadeus means “love of God.” Amadeo is the Italian and Spanish name equivalent.

APOLLO

A name borrowed from a Greek god, Apollo was boosted by singer Gwen Stefani when she gave the name a son in 2014.

ARMANDO

Take Herman, send it through the romance language-izer, and sophisticated Armando emerges. Fun fact: it’s the given name of Miami-born megastar Pitbull.

ARNO

A river in Tuscany, or possibly a short form of Arnold. The French Arnaud looks like it ends with a consonant, but it’s also pronounced like Arno.

BENICIO

Parents love Ben names, from Benjamin to Bennett to Benedict. Benicio shares roots with that last one, both derived from the Latin benedictus – blessed.

BRANDO

A Hollywood surname that feels like an update to 90s favorites like Brandon.

BRAULIO

A seventh century saint’s name, Braulio might mean sword. Or possibly it means bright. Either way, it’s a rarity that fits in with tough guy o-enders like Rocco and Bruno.

BRIO

To play con brio indicates that musicians should play in a lively fashion. After generations of boys named Brian and Bryce, Brio isn’t a stretch.

BRUNO

Once reserved for the heavy in gangster movies, Bruno now carries all the charm and sophistication of Bruno Mars.

CAIRO, KAIRO

Place names are fair game, from Hudson to Savannah. The Egyptian capital is spelled with a C, but parents preferred the K spelling for their sons in 2018.

CALIXTO

Meaning “most beautiful,” Callistus had a good run in the ancient world. Calixto is a Portuguese and Spanish name used more recently.

CALOGERO

Like Calixton, Calagero’s first syllable means beautiful, ultimately from the Greek kalos. Actor Chazz Palminteri of A Bronx Tale and Modern Family, was born Calogero.

CAMILO

A little bit Cameron, a little bit Milo, Camilo combines a modern sound with ancient roots. It’s the Spanish form of the Latin Camillus.

CARMELO

Basketball star Carmelo Anthony put this unusual name on the map when he was a first-round draft pick in 2003. His long and successful career continues, as does his influence on boy names ending with o.

CATO

The name of an ancient Roman statesman, Cato means wise. It took on a different sheen when the OJ Simpson trial propelled Kato Kaelin to reality star-status. But the next generation might see it as more of an ancient name, thanks to its use in The Hunger Games.

CIELO

The Spanish word for sky as well as heaven, Cielo feels a little bit nature-name, and a little bit spiritual, too.

CISCO

Short for Francisco. Back in the early 1900s, the author O. Henry invented the villainous Cisco Kid. By the time the character made it to television during the 1950s heyday of Westerns, he was more of a Robin Hood figure. It’s a Francis name, hold the Fran.

CORRADO

Change a few letters, and the entire vibe of a name is transformed. Corrado is the Italian form of Conrad. The latter feels buttoned-up and traditional; on the other hand, Corrado sounds more like a romantic hero.

CIRO

The Spanish and Italian form of Cyrus, Ciro could fit right in with Mateo and Luca.

COSMO

The perfect name for parents seeking something that feels as big as the universe, but also as specific as a flower. Both are referred to as cosmos. Cosmas was a fourth century saint.

CRISTIANO

Another name from the world of sports, Cristiano Ronaldo is a Portuguse footballer widely regarded as one of the best players of all time.

CRUSOE

A literary surname name just right for an adventurous family.

DARIO

Italian Dario comes from a Persian name meaning “possessing goodness.”

DARROW

A surname name that brings to mind legendary attorney Clarence Darrow.

DEANGELO

Angelo’s surname cousin.

DELANO

A surname name, borrowed from former president Franklin Delano Roosevelt. It was his mother’s maiden name.

DENIRO

Another Hollywood-inspired surname, DeNiro is all Robert.

DOMENICO

The Italian cousin to popular choice Dominic.

DRACO

A constellation, Draco means “dragon” in Greek. It’s also the name of Draco Malfoy, Harry Potter’s long-time adversary.

ELISEO, ELISIO

We love Elijah and Elias. Eliseo belongs to the same family, a name that feels modern, but claims Old Testament roots.

EZIO

One of Zoe Saldana’s sons is Bowie Ezio. The middle name means eagle. If you’re worried that Enzo feels too common, Ezio could substitute nicely.

FERNANDO

It’s tough to see this name and not break into the ABBA song. It’s cousin to the classic Ferdinand, and shortens to nickname Nando.

FLAVIO

Flavius was an old-school Roman family name meaning “golden.” Flavio is a romance language update.

FRANCISCO

If Diego fits, wtih ties to a California city and a popular saint, then Fransicso must, too. Lin-Manuel Miranda gave the name to their second son in 2018.

GALILEO

Stargazers, look no further for your son’s name! Worried that being named for world-changing astronomer Galileo Galilei is too much? It shortens to Leo.

GEO, GIO

It could be short for any of the Italian Gio names, from Giovanni to Giorgio. And Geo might even serve as an unexpected George nickname.

GIANCARLO

Romance language smoosh names could inspired their own list. Gianfranco, Joseantonio, and more occur sometimes in English – and far more regularly in languages like Spanish and Italian.

GINO

Italian names are often lengthened … and then shortened again. So Luigi becomes Luigino, and then shortens to Gino.

GIORGIO

Italian form of classic favorite George.

GUILLERMO

The Italian, Spanish, and Portugeuese form of William, made famous by Mexican filmmaker Guillermo del Toro.

HERO, HIRO

This name might make you think of ancient heroes of legend and mythology. That’s partially true, but it’s also a Japanese given name. It’s gender neutral, famously used for one of Shakespeare’s female characters in Much Ado About Nothing.

HORATIO

Hornblower. Alger. There’s something jaunty about Horatio, a name that feels big and bold.

IGNACIO

The Spanish form of saintly, fiery Ignatius. In Italian, it’s Iganzio.

INDIGO

A blue baby name with unisex potential.

INDIO

Robert Downey Jr.’s eldest son was named for the California city that hosts the annual Coachella Festival.

ISIDRO

Isidro comes from Greek name Isidore.

IVO

One of many names related to the Germanic element meaning “yew tree.” The spelling Yvo is sometimes seen, too.

JAGO

The Cornish form of Jacob, which makes Jago a cousin to evergreen James.

JAIRO

Jairo is the Spanish form of the Old Testament name Jair. It’s got a great meaning – he shines.

JERICHO

Perhaps the oldest continuously occupied city in the world, Jericho falls somewhere between traditional picks like Jerome and modern boy names ending in o.

JETHRO

An Old Testament name, Jethro has a great meaning – abundance. To some, it’s probably stuck on the Beverly Hillbillies, but it could also read as a bold, homespun choice, an alternative to rising choices like Arlo.

KAHLO

Surname of famous painter Frida Kahlo.

KELSO

A Scottish surname borrowed from a place, Kelso screams That ’70s Show to a certain generation. But in 2023, YouTubers Taylor – aka “Dude Dad” and Heidi Calmus gave the name to their son, inspired by a Colorado mountain. At least a dozen other states also boast places called Kelso, most of them named for people with the surname.

KENZO

Take the Italian Enzo, add a K, and suddenly you’ll have the Japanese Kenzo. Designer Kenzo Takada used the name for his luxury brand.

KYLO

It sounds like Kylo-with-an-o, which could be an appealing sound. Star Wars fans know that Kylo Ren is the villain for much of the latest installment in the series.

LANDO

You might think of Star Wars‘ Lando Calrissian. This was originally a romance language form of Lance. Lanzo is a a name of German origin that shares the same roots.

LASZLO

Laszlo is the Hungarian form of Vladislav, via the Latinized form, Ladislas. The spelling is confusing; doubtless that’s why we’ve seen Lazslo and Lazlo in the US, too. Though they’re all quite rare.

LAZARO

The Spanish form of New Testament name Lazarus might make an intriguing choice.

LEANDRO

Leander comes from Greek myth, a name formed from “lion” and “man.” It’s Leandro in romance languages – possibly even fiercer than the original.

LONZO

Made famous by the NBA’s Lonzo Ball.

LUCIANO, LUCO

Long and elaborate Luciano turns Luke, Lucas, Luca, and even Lucian up to eleven. As for Luco, it feels like a twist on Luca, inspired by Nico.

MACEO

Most likely a cousin to Mateo, Maceo offers a long and impressive history. But despite Halle Berry choosing the name for a son in 2013, Maceo has yet to catch on.

MANOLO

Born Manuel, shoe designer Manolo Blahnik rose to fame and pop culture prominence during the 1990s.

MARCELO, MARCELLO, MARCO

Marcel is seldom heard, but add an ‘o’ and the name changes. It’s derived from Roman name Marcus, the same source for Marco. Marco appears in not one, but two, Dr. Seuss stories.

MARIO

An iconic Italian choice.

MASSIMO

An Italian Max name, hold the X.

MAXIMILIANO, MAXIMO

Mini name Max feels complete with just three letters. Maximo adds plenty of drama to the name. The elaborate – six syllables! – Maximiliano takes it farther still.

MICHELANGELO

Another Renaissance Artist/Teenage Mutant Ninja Turtle name, and another romance language smoosh, Michelangelo comes in at a dramatic five syllables.

MIKO, MIKKO

The Finnish form of Michael.

MIRO

The Slavic element miru means peace. Think of Russian space station Mir. There’s also Spanish sculptor Joan Miro, and the Latin mirus, root of our word miracle.

MOROCCO

Borrowed from the country in northwest Africa. Mariah Carey and Nick Cannon named their son Morrocan, inspired by the decor style in Carey’s NYC apartment.

NEO

Neo means new, but it also means Keanu Reeves’ character in 1999’s The Matrix, plus all the sequels that followed.

NICOLO, NICCOLO

Machiavelli and Paganini answered to this first name, a romance language spin on traditional Nicholas.

ORLANDO

A romantic hero name boosted by Hollywood star Orlando Bloom.

OSLO

Another place name, this one the capital of Norway. It might mean “mouth of the river,” but that’s subject to debate.

OSVALDO

Oswald feels antique, possibly too much. But Osvaldo’s v and o combination might put it on the same track as Alvaro.

OTHELLO

The name’s exact roots are debated, but we know the name thanks to Shakespeare’s tragedy.

PAOLO

There’s some poetry to Paolo, the Italian form of classic Paul.

PABLO

Picasso’s first name is the Spanish form of Biblical standard Paul.

PEDRO

The Spanish form of Peter, Pedro still reminds many of 2004 indie hit Napoleon Dynamite.

PHARAOH

Royal names have been big, from Kingston to Reign. Why not Pharaoh?

PIERO, PIETRO

Pedro is the Spanish, while Piero and Pietro are Italian forms of classic Peter. If you know your Avengers, Pietro is the given name of Quicksilver.

RICARDO

When it comes to boy names ending with O, so many come to use from Romance languages. Ricardo is Spanish and Portuguese.

ROCCO

Rocco made headlines when Madonna and Guy Ritchie gave this saintly, Italian heritage choice to their son way back in 2000.

ROMEO

It’s not just the Beckhams naming their son Romeo. This Shakespearean name takes a little something from Roman, and a lot from boy names ending in o.

RODRIGO

The Germanic Roderick, by way of Spain.

ROGELIO

Probably a cousin to Roger. There’s a ninth century Saint Rogellus, a martyr from Cordoba, Spain.

ROSCOE

Once relatively common, Roscoe has become rare, but might qualify as a neglected gem.

SERGIO

Sergius is the Latin, Sergei the Russian, and Serge the English – though we’re never embraced the latter. Sergio fits right in with so many romance language boy names.

SHILOH

The Jolie-Pitts gave this name to a daughter, but they weren’t the first to use it. A Biblical place name, as well as the site of a Civil War battle, Shiloh has seen sparing use for years. It offers a great meaning: tranquil.

TADEO

New Testament Thaddeus has never felt mainstream. Maybe Tadeo, the Spanish version, will.

TEO, TEODORO

A romance language twist on o-ender Theo.

TULIO, TULLIO

From the Roman name Tullus, though the exact meaning is unclear. Surname Tully is most often Irish and has separate roots.

TYCHO

The name of a famous Danish astronomer, stands-out Tycho shortens to fits-in Ty.

VALENTINO

It brings to mind 1920s screen legend, Rudolph Valentino – born Rodolfo Alfonso Raffaello Pierre Filibert Guglielmi di Valentina d’Antonguolla. Valentina is big for girls, too.

VIGGO

Actor Viggo Mortensen helped make this name familiar. It’s Norse in origin and can be a diminutive for traditional choices like Alvig and Vigfrid.

VINCENZO

The Italian form of Vincent.

WINSLOW

A surname name that brings to mind American landscape painter Winslow Homer, this name feels a little less serious than Winston.

What are your favorite boy names ending in o?

First published on October 16, 2015, this post was revised substantially and re-posted on May 7, 2020; July 25, 2022; April 11, 2023; and February 23, 2025.