1770+ Boy Names Ending in O

Zio is a pet form for names ending with 'zio', such as Maurizio, Marzio and Tiburzio. As a full name in Italian, though it wouldl be like naming your son Uncle Uncle.

Being a modern word, Halo didn’t become used as a name until around the nineteenth century. Halo is now mostly given to girls, and has become more common since the Halo video game series was released in 2001, in which Halo rings are huge structures used as weapons, but do have a religious connection. A space age virtue name and possible honour name for Gloria.

The literal meaning of Adagio is 'at ease.' Adagio's use for a slow musical passage or ballet is contradicted by its lively sound and feel.

Guido was very popular in Renaissance Italy, with many namesakes including painter Fra Angelico (born Guido di Pietro) and mathematician Guido Fubini. Guy Fawkes, of gunpowder plot fame, sometimes used this version. Nowadays it's unfairly overlooked, but in the current trend for snappy international names ending in -o, this cultured gem deserves more use.

Both the Spanish Marcelo and Italian Marcello would work well for children of any backgrounds. The name has been in the US Top 1000 consistently since the mid-90s and has been steadily climbing upwards. Deriving from the Roman family name, Marcellus, itself a diminutive of Marcus, Marcelo currently ranks above Marcello and Marcel in the states.

When actress Rachel Griffiths chose this highly unusual name for her son, many assumed it was a bizarre invention. But a noted Australian poet (Griffiths is an Aussie) is known by this name.

With an X at the start and an O at the end, Xeno is undeniably modern and cool. If you're looking for a derivation, it could come from either the Greek male name Xenon, meaning "foreigner"; of from Zeno, a latinized form of the Greek name Zenon, meaning "dedicated to Zeus".

Kato gained a lot of attention during the O. J. Simpson trial via witness Kato Kaelin (born Brian). It is also the name of a fictional character in "The Green Hornet." Spelled Cato, it has a lot more credibility as an ancient name.

More common as a dog name than a baby name for now, but that hasn't stopped Milo and Rex rising back up the charts! Lovers of edgy o-ending names like Otto, Arlo and Cosmo might like this starry-eyed possibility.

Io is most familiar to English speakers as a female name from Greek mythology, but in Japan it's used for both sexes.

Alfredo, Italian, Spanish and Portuguese variation of Alfred, is most familiar as the romantic lead in Verdi's evergreen opera La Traviata. On a less romantic note, Alfredo is also the name of a pasta sauce.

Cassio is a notable Shakespearean name that's a member of the ever-more-popular Cassius family of names. Cassio was Othello's young, good-looking, and flirtatious lieutenant.

Has a lot of energy and charm, as does the Italian form, Taddeo.

Yet another winning international form of Peter.

Eilo is one of the few masculine names to derive from a feminine one. It comes from Eila, the Norwegian variation of Elina.

A romantic choice, this appealing Spanish name for boys is both accessible and distinctive.

The Roman god of the underworld, the former ninth planet, a cartoon dog...but not a baby.

With its musical allusions, a harmonious possibility.

This sleek Italian name was raised from the dead by Mexican Mozart in the Jungle star Gael Garcia Bernal, who chose it for his son (he also has a daughter named Libertad). For athletic inspiration, Lazaro Alvarez, boxing for Cuba, is the three-time world champion lightweight boxer. Lazarus and root name Eleazar are both also destined for comebacks.