
Antonio vs. Antonia. Gino vs. Gina. Mario vs. Maria. We’re used to -o endings pointing to male names and -a endings to female. But parents today want names that stand apart from the pack, with the potential to surprise us. For a growing number, that means flipping the script on final letters.
-A names like Ezra and Luca are now fast-rising hits for boys. Meanwhile parents of girls have been tiptoeing toward -o endings, starting with what I call “hidden o names.” These showcase the unconventional feminine -o sound but cushion the spelling with silent letters: Willow, Shiloh, Margot.
I first described the “hidden o” trend back in 2014. Since then the growth of hidden-o names has accelerated, so names like Monroe and Marlowe rank in the US top 1000. And in the past few years, the actual -o ending has started to join the party. Girls’ -o names are now at the point where hidden o’s were at the time of the original article.

Girls’ -o names surged once before, in the middle of the 20th century. That spike was all about the nickname Jo, which singlehandedly accounted for three-quarters of the era’s -o girls. This time, no single name is taking the lead. The new -o surge is a phenomenon of pure sound, spread out across dozens of rare but rising names. They include:
- The few established English female -o names, like Cleo and Margo
- Contemporary English word names like Halo and Indigo.
- Names from other languages like Cielo (Spanish, “heaven/sky”) and Emiko (Japanese; multiple meanings depending on the kanji used)
- Nicknames from around the world like Lilo and Coco
- Names of female figures from classical mythology, like Juno and Echo
Notably, none of the top ten girls’ -o names are traditional male names. That suggests that the trend isn’t about sounding masculine per se. It’s more about staking out new fashion ground with names that capture attention.
4 Comments
I believe -ko is a common girl’s name ending in Japanese
Who would want to name anyone Echo? Only someone who wants the kid to follow everybody else, and softly.
Or someone who already named a kid Siri.
Echo was the name of a nymph in Greek mythology. I think it’s a beautiful name with a cool sound. The name came before the word, anyways. And Siri is a name, too, and a really pretty one.