Baby Name of the Day Cosmo: Worldly and Upbeat

The baby name Cosmo is out of this world … and completely down to earth, too.

Thanks to Lola for suggesting our Baby Name of the Day.

WHAT DOES THE NAME COSMO MEAN?

The Greek kosmos originally meant “orderly arrangement.”

Sometime around the 6th century BC, ancient Greek philosopher Pythagoras used the word to refer to the universe as a whole.

Today, cosmos continues to refer to the world in the widest sense. Cosmic refers strictly to the stars and objects in the solar system and beyond.

And if you’re cosmopolitan? Then you’re someone at home anywhere. Though a closer synonym for cosmopolitan is sophisticated, not astronaut, so there’s a slightly different vibe.

You might hear the baby name Cosmo and think of two things:

• Cosmo, the women’s magazine, debuted way back in 1886. 
• And the cocktail? An early version was created way back in the late 1920s, but the drink reached its current form in the mid-1980s and became famous thanks to the long-running Sex and the City series. 

It’s been a given name for even longer.

SAINT COSMO

During the 3rd century, brothers Cosmo and Damian used their medical training to help those too poor to afford services. 

They died as Christian martyrs during the Diocletian persecutions. They’re both considered saints. 

Just like any saint’s name, it spread across the Western world. Other forms evolved:

• The saint was probably named Cosmas.
• It became Cosimo in Italian. The powerful de Medici Renaissance family embraced it.
• During the 1700s, the Duke of Gordon named his son Cosmo, bringing it to broader use in the English-speaking world.

In fact, British Cosmos pop up in the history books from the 18th century onward.

Where did a Scottish aristocrat find an Italian name? The Duke’s dear friend was Cosimo III de’ Medici, Grand Duke of Tuscany, who reigned for a record-setting 53 years. It’s worth noting that the Tuscan ruler was something of a disaster.

But that’s so far in the distant past that it doesn’t touch the baby name Cosmo now.

20th CENTURY COSMO

By the 20th century, the name read less as a saintly, pan-European choice and more as an offbeat, unexpected character.

• In 1926 novel turned 1937 movie Topper, staid banker Cosmo Topper has his life transformed by a pair of fun-loving ghosts, played by Constance Bennett and Cary Grant. Sequels followed. Remakes, too, the most recent in 1979.
• The cast of 1952’s Singin’ in the Rain included Cosmo, the comic foil played by Donald O’Connor to leading man Gene Kelly and newcomer Debbie Reynolds.
• Brigham Young University’s mascot is Cosmo the Cougar.
• If you know your Nickelodeon animated series, the long-running Fairly OddParents featured Cosmo and Wanda as Timmy Turner’s fairy godparents.
• One more from the world of animation: Cosmo Spacely served as George Jetson’s demanding boss at Spacely Sprockets on cartoon The Jetsons.
• To Seinfeld fans, it’s all Cosmo Kramer, the resident of Apartment 5B.

NATURE NAME

Typically known as cosmos, the flower in a cousin to the daisy. Varieties are found throughout the Americas and beyond. 

Scarlett Johansson and Colin Jost named their son son Cosmo in 2021. He joins older sister Rose from Scarlett’s first marriage. In some respects, the siblings’ names are very different, but they’re linked by their subtle botanical meaning.

ARLO, LEO, THEO, MILO

Boy names ending with o have gone from rising style stars to mainstream favorites. As of 2025, the US Top 100 includes Mateo, Leo, Thiago, Enzo, Theo, and Theodore, as well as Beau. 

Names like Milo, Arlo, Hugo, and Nico aren’t far behind. 

In this company, the baby name Cosmo feels only slightly daring.

HOW POPULAR IS THE NAME COSMO?

The baby name Cosmo dipped into the US Top 1000 just a handful of times during the 1910s and 20s. 

As of 2020, 57 newborn boys received the name. That’s a leap from just 22 in 2000, or 25 in 2010. But it’s still incredibly rare, too.

The baby name Cosmo appears in the US Top 1000 just four times, in 1913, 1921, 1925, and 1926.

It reached peak popularity with 99 births in both 2022 and 2024. As of 2025, the name was given to just 80 boys. 

This just under-the-radar status reinforces Cosmo’s quirky charm. 

WORLDLY and UPBEAT

Cosmo bridges the familiar and the distinctive. It blends a long history of use, an appealing meaning, and plenty of current style. 

If you’re after a truly uncommon blends-in/stands-out choice for a son, Cosmo might be worth a closer look. 

What do you think of the baby name Cosmo?

First published on June 29, 2008, this post was revised substantially and re-posted on September 17, 2012; August 19, 2021; and October 21, 2026.