NameCensus.

UK boy's name

Cillian

Little freckled or fair-haired one of Irish origin.

For 2026, the newest official UK baby-name figures on this page are from 2024. That release is the current official benchmark rather than a forecast.

Cillian is a boy's name in the UK records. People looking for Cillian popularity in 2026 should use the latest official release, which is 2024 in this profile. In that release it ranked #177, with 285 babies registered with the name. Its strongest year in the published records was 2024, with 285 births.

This profile covers 2,306 England and Wales registrations across 29 recorded years from 1996 to 2024. The figures come from ONS England and Wales, NRS Scotland and NISRA Northern Ireland, so the page is a view of published baby-name registrations rather than a forecast or a live count of people using the name today.

Cillian is at its recorded peak in the England and Wales series.

We estimate that about 4,332 living people in the UK are called Cillian. This uses published birth registrations from England and Wales, Scotland and Northern Ireland, then applies ONS national life tables to estimate how many are likely still alive. It does not forecast extra births for 2025 or 2026.

Key insights

  • Cillian ranked #177 for boys in England and Wales in 2024, with 285 registrations.
  • The name peaked in 2024, when 285 boys were registered as Cillian.
  • Cillian ranks best in Northern Ireland in the latest published regional snapshot for that area, where it placed #2 in 2024.
  • About 4,332 living people in the UK are estimated to have Cillian as a first name, after adjusting past birth registrations with ONS life tables.

Latest rank (E&W)

#177

2024

Births in 2024

285

Latest year

Peak year

2024

285 births

Estimated living

4,332

2026

Meaning

What does Cillian mean?

The name Cillian is an Irish Gaelic name that originated in ancient Ireland. It is derived from the Old Irish word "cill," which means "church" or "monastery." The name was likely given to children who were born or raised in the vicinity of a church or monastic settlement.

The earliest recorded use of the name Cillian dates back to the 6th century AD, when it was borne by several Irish saints and scholars. One of the most notable figures was Saint Cillian, a Irish missionary who traveled to France in the late 6th century to spread Christianity. He is venerated as the patron saint of several towns and villages in Brittany.

In the medieval period, the name Cillian was popular among the Irish nobility and clergy. It was often associated with religious devotion and scholarly pursuits. Several Irish kings and princes bore the name, including Cillian mac Congail, a 7th-century King of Bregia, and Cillian mac Scandail, a 9th-century King of Munster.

The name also appears in some of the oldest surviving Irish literary works, such as the Annals of Ulster and the Annals of the Four Masters. These historical chronicles record the lives and deeds of notable individuals bearing the name Cillian.

In more recent times, several notable figures have carried the name Cillian. These include Cillian Murphy (born 1976), an Irish actor known for his roles in films such as "28 Days Later" and "Inception," and Cillian O'Connor (born 1992), an Irish Gaelic footballer who plays for Mayo.

Other notable individuals named Cillian throughout history include Cillian de Nobilibus (c. 1345-1368), an Italian Franciscan friar and writer; Cillian of Derry (d. 682), an Irish saint and Bishop of Derry; and Cillian of Inishbofin (d. 670), an Irish saint and founder of a monastery on Inishbofin Island.

Sourced from namecensus.com.

Popularity

Cillian over time

The chart below shows babies named Cillian registered in England and Wales in the years where the name appears in the published records, from 1996 to 2024. Empty years are left out so rare names are not stretched across long periods where the published files do not show any registrations.

For Cillian, the clearest high point is 2024. The latest England and Wales figure is 285 births in 2024, compared with 285 at the peak.

Babies born per year

Cillian
071143214285199620102024

Decades

Cillian by decade

Decade totals smooth out the yearly jumps and make it easier to see whether Cillian was a short-lived spike or a name that stayed in regular use. Average rank is calculated only from years where a published rank exists.

Decade Average rank Total births Years covered
2020s #223 1,123 5
2010s #519 998 10
2000s #1592 163 10
1990s #2321 22 4

Geography

Where Cillian is most common

The bars show the latest published local birth counts for Cillian. They are useful for spotting where the name is showing up in real numbers, while the rank beside each bar shows how strongly it performs inside that region.

Cillian ranks best in Northern Ireland in the latest published regional snapshot for that area, where it placed #2 in 2024.

Northern Ireland
142
Scotland
62

Across the UK

Cillian in Scotland and Northern Ireland

Scotland (NRS)

#83 in 2024

18 years of NRS records, 452 total registered

Northern Ireland (NISRA)

#2 in 2024

28 years of NISRA records, 1,599 total registered

Notable bearers

Famous people named Cillian

  • Cillian Vallely

    musician

    Irish musician

    1972-

Related

Names similar to Cillian

FAQ

Cillian: questions and answers

How popular is the name Cillian in the UK right now?

In 2024, Cillian was ranked #177 for boys in England and Wales, with 285 births registered.

When was Cillian most popular?

The peak year on record was 2024, with 285 babies registered as Cillian in England and Wales.

What is the meaning and origin of Cillian?

Little freckled or fair-haired one of Irish origin.

How many people are called Cillian in the UK?

A total of 2,306 babies have been registered as Cillian across the 29 years of ONS England & Wales records shown here, plus 452 more in Scotland and 1,599 in Northern Ireland.

Where is Cillian most common?

In the latest published local rankings, Cillian ranks best in Northern Ireland, where it placed #2 in 2024. The regional bars on this page use birth counts, so they also reflect the size of each region.

Which records is this page based on?

The England and Wales timeline uses ONS baby-name records. Scotland figures come from NRS and Northern Ireland figures come from NISRA. Counts are registrations in published baby-name files. The living estimate uses those birth registrations with ONS national life tables.