1770+ Boy Names Ending in O
Across 109 pages
of 109
About this list
Boy names ending in O offer many intriguing options, from such top names as Theo to unique O-ending names from Kylo to Zino.
Mateo is the most popular boy name ending with O right now, though there are nearly 100 O-ending boy names among the US Top 1000. Along with Mateo, other boy names in the US Top 1000 include Leo, Santiago, Diego, Romeo, and Antonio.
And there are hundreds more unique names for boys that end with the letter O worthy of your consideration. These range from the biblical Jethro to the ancient Greek Cosmo to the cool, modern Rio and Po.
Here are all Nameberry’s boy names that end with the letter O, ordered by their current popularity on Nameberry.
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The names
Mateo
Spanish
"gift of God"
Mateo is a Latinate name that like Mia and Luca, is becoming popular far beyond its native Spanish community. With its fresh feel and charm, it made a surprise entrance to the boys' Top 10 in 2023.…
Leo
Latin
"lion"
Leo is a strong-yet-friendly name that was common among the Romans, used for fourteen popes, and is now at its highest point ever in the US. Brave but sparky, Leo has ranked in the Top 20 in the US,…
Santiago
Place-name or Latin
"Saint James"
Santiago is a spirited Spanish name with great crossover potential. It's a place-name (a city in Chile), a surname, and the name of the patron saint of Spain. Santiago has been rising through the…
Thiago
Spelling variation of Tiago, diminutive of Santiago
"supplanter"
Some high-profile soccer stars, such as Thiago Silva, have contributed to its success. The correct Portuguese pronunciation is chee-AH-go. Thiago is ranked Number 2 for boys in Puerto Rico.
Enzo
Italian variation of Henry, German
"estate ruler"
You may be surprised to know that Enzo is now a Top 100 boy name in the US and the UK, where it has been climbing straight uphill since the turn of this century. Enzo originated as the Italian…
Theo
Diminutive of Theodore
"gift of God"
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. Now in the Top 100 in this form, Theo's…
Leonardo
Italian and Spanish variation of Leonard, German
"brave lion"
For centuries this name was associated primarily with the towering figure of Italian Renaissance painter-scientist-inventor Leonardo da Vinci, and was scarcely used outside the Latin culture. But…
Emiliano
Italian and Spanish variation of Emil
"rival"
Emiliano is an appealing Latinate version of Emil, with the same gentle sounds but additional flair. Popular in Chile and Mexico, where it ranks in the Top 20, Emiliano is also a rising name in the…
Lorenzo
Italian; Spanish, variation of Laurence
"from Laurentium"
Latinizing Lawrence gives it a whole new lease on life. Like Leonardo, Lorenzo has been integrated into the American stockpot of names, partly via actor Lorenzo Lamas. Other associations are with…
Milo
Latin and Old German
"soldier or merciful"
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…
Matteo
Italian
"gift of God"
This attractively energetic Italian version of the classic Matthew is primed to move further and further into mainstream American nomenclature. Mateo is technically the Spanish version, but many…
Arlo
Irish or English
"between two hills"
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. Along with its Irish and English…
Emilio
Spanish and Italian variation of Emil
"rival"
Dashing and suave, with a hint of poetry and gentleness, Emilio is an appealing and international choice. A solid favorite in Italy, it is also on the rise in the US, France, Austria, and the UK.…
Diego
Spanish variation of James
"supplanter"
The energetic Diego is rising rapidly along with a lot of other authentically Spanish baby names that work perfectly well with surnames of any origin. Possibly a derivative of Santiago, Diego is a…
Nico
Italian diminutive of Nicholas, Greek
"people of victory"
Nico is one of the great nickname names, full of charm, energy and effortless cool -- a neo Nick. Nico is commonly heard in Italy -- as a short form of Niccolo -- and also in France, Belgium,…
Antonio
Spanish and Italian variation of Anthony
"from Antium"
Antonio is a Shakespearean favorite -- the Bard used it in no less than five of his plays, and has long been a ubiquitous classic in Spanish-speaking countries, where the nickname Tonio is also…
Alejandro
Spanish variation of Alexander
"defending men"
Softer and smoother than Alexander, this classic Spanish name for boys has made a seamless transition to this culture. Adding to its current impact: the Lady Gaga song Alejandro .
Kairo
Spelling variation of place-name Cairo, Arabic
"the conqueror"
Contemporary Kairo fits in with the modern trend of substituting a C for a K initial, and in this case, it works to get you more easily to the cool nickname Kai. In fact, parents in the US and the UK…
Otto
German
"wealthy"
Otto is cool again. Long a quintessential Old Man Name, Otto has been promoted to trending darling of adventurous baby namers. Like most German names , Otto fell out of favor during and after the two…
Maximiliano
Spanish
"greatest"
This is a Spanish variation of Maximilian that has begun to gain some popularity. It has a luxurious feel -- maybe it's the suggestion of "millions"? -- but this is one of those Spanish baby names…

