Cailo
A masculine name of uncertain origin, possibly derived from Spanish.
Name Census estimates that about 13 living Americans carry the first name Cailo. The name is used almost exclusively for boys. The average person named Cailo today is around 2 years old, and the year with the single highest number of Cailo births was 2024 (7 babies).
This page is the full Name Census profile for Cailo. Below you will find a gender breakdown showing how the name splits between male and female registrations, a year-by-year popularity chart stretching back to 1880, decade-level totals, the top US states for this name, its meaning and etymology, and a set of frequently asked questions with data-backed answers.
For a British comparison, Name Census UK has a UK baby-name profile for Cailo with official rankings and popularity over time.
Key insights
- • Fewer than 100 living Americans are believed to carry the name Cailo. It is among the rarest names in the SSA records.
People living today
13
~ 1 in 26,365,718 Americans
Peak year
2024
7 babies that year
Average age
2
years old
2024 SSA rank
#10,030
Tracked since 2023
Popularity
Cailo: popularity over time
Babies born per year
Decades
Cailo by decade
The table below breaks the full SSA timeline into ten-year windows. Each row shows how many male and female babies were given the name Cailo during that decade, along with a combined total. This is useful for spotting eras where the name surged or retreated.
| Decade | Male | Female | Total |
|---|---|---|---|
| 2020s | 13 | 0 | 13 |
Origin
Meaning and history of Cailo
The name Cailo is believed to have originated from the ancient Celtic language, spoken by various tribes and communities across Western and Central Europe during the Iron Age and the medieval period. Its roots can be traced back to the Proto-Celtic word "cail," which meant "slender" or "lean."
One of the earliest known references to the name Cailo can be found in the ancient Irish epic, the Táin Bó Cúailnge, which dates back to the 8th or 9th century AD. In this epic, Cailo is mentioned as a prominent warrior and chieftain of the Ulaid people, a powerful Celtic tribe based in modern-day Northern Ireland.
During the Middle Ages, the name Cailo gained popularity among the Celtic populations of the British Isles, particularly in Ireland and Scotland. In the 12th century, a Scottish nobleman named Cailo MacAulay was recorded as a prominent figure in the court of King David I of Scotland.
In the 15th century, a renowned Irish poet and bard named Cailo Óg Ó Duibhgeannáin gained fame for his intricate and lyrical compositions, which were widely celebrated among the Gaelic nobility of the time.
Another notable figure bearing the name Cailo was Cailo Ó Maolchonaire, an Irish chieftain and warrior who lived in the 16th century. He was renowned for his military prowess and his role in the legendary Siege of Dunluce Castle during the Nine Years' War in Ireland.
As the centuries passed, the name Cailo continued to be used sporadically across various Celtic regions, although its popularity waned in comparison to other more common Irish and Scottish names. Nevertheless, it has maintained a presence in certain areas, particularly in parts of Ireland and Scotland, where it is still occasionally bestowed upon newborns as a nod to their ancestral heritage.
People
Cailo + last name combinations
How many people share a full name with Cailo as the first name? Click a combination below to see the estimate, or search any pairing.
Related
Other names starting with C
Other first names starting with C with a similar number of bearers.
FAQ
Cailo: questions and answers
How many people in the U.S. are named Cailo?
Name Census puts the figure at roughly 13 living Americans. We arrive at this by taking every SSA birth registration for Cailo going back to 1880 and adjusting each cohort for expected survival using CDC actuarial life tables. The result is an age-weighted living-bearer count, not a raw birth total. That works out to about 1 in 26,365,718 US residents.
Is Cailo a common name?
We classify Cailo as "Very Rare". It ranks above 33.2% of all first names in the SSA dataset by living bearers. Across the full history of the data, 13 babies have been registered with this name.
When was Cailo most popular?
The single biggest year for Cailo was 2024, when 7 babies received the name. The fact that the average living Cailo is about 2 years old gives you a rough sense of which era contributed the most bearers who are still alive today.
What does the SSA popularity chart show?
The chart tracks births, not the number of people alive with the name today. Each point shows how many babies were given the name Cailo in that year. That makes it useful for spotting when the name rose, peaked, or faded.
Is Cailo a male name?
Yes, 100.0% of people registered as Cailo in the SSA data are male. You can see the full per-sex comparison in the gender distribution section above, which includes the latest year rank, birth count, and peak year for each sex.
Is Cailo still being used today?
Yes. The SSA still recorded Cailo in 2024, and the page above shows its latest-year rank where available. A name can be well past its peak and still remain in steady use, especially if it built up a large population over earlier decades.
Why can a name have a lot of living bearers even if it is not trendy now?
Because living-bearer counts and current baby-name popularity measure different things. A name like Cailo can build up a very large population over many decades, even if fewer parents are choosing it now than they did at its peak.
Where does this data come from?
First-name figures come from the Social Security Administration's national baby name files, which cover every name on a birth certificate from 1880 to 2024. Living-bearer estimates layer in CDC actuarial life tables broken out by sex to account for mortality. The population baseline (342,754,338) is the Census Bureau's latest national estimate. You can read the full calculation on our methodology page.
Does every first name have Census demographic data?
No. The public Census first-name release only covers names that met the Bureau's publication rules, so many rarer names in the SSA files do not have a published Census demographic snapshot. In those cases, the page still shows the SSA trend, gender history, and state data.
How many people share the name Cailo?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.