1770+ Boy Names Ending in O

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.

One of the best known early Nemos was the captain in Twenty Thousand Leagues under the Sea, while the more familiar modern one is the animated little orange fish in the Disney movie. Unusual name well worth considering. By the way, there is also a Shakespearean Nemo and one in Dickens's Bleak House. An enchanting early comic strip by Winsor McCay was called Little Nemo.

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.

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.

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.

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.

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.

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.

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".

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

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

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.

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.

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

Yet another winning international form of Peter.

Giacomo is a primo member of the Giovanni-Gino-Giancarlo-Giacomo gruppo of Italian names that are beginning to be adopted by American parents. Singer/creative baby namer Sting chose it for his son.

Iago, the villain of Shakespeare's Othello, was so treacherously evil that his name has hardly ever been heard offstage. Try the much-more-benign Inigo.

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

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