Cillian vs Killian
Cillian and Killiancompared on official birth-registration statistics and Namewise's recorded data. This page states what each name's record shows — it never picks a winner or scores one name against the other.
Head to head
Ranks are only compared within one published list and one year. Two ranks from different years, from a boys' and a girls' list, or from different registrars are not comparable, so they are not placed side by side.
Northern Ireland · Boys
In 2024, Cillian was ranked #2 and Killian #187 among boys in Northern Ireland.
Republic of Ireland · Boys
In 2025, Cillian was ranked #9 and Killian #141 among boys in Republic of Ireland.
Scotland · Boys
In 2024, Cillian was ranked #83 and Killian #268 among boys in Scotland.
England and Wales · Boys
In 2024, Cillian was ranked #177 and Killian #638 among boys in England and Wales.
Cillian and Killian over time
Cillian and Killian appear together in 3 published lists, across 111 years of shared records. Cillian held the stronger position in more years in 3 of them, Killian in 0.
The order between them changed and held in 2 of those lists — a change in that published list, never a claim that one name displaced the other.
Killian reached its own highest recorded position earlier in 3 of those lists, and Cillian in none. Each position is a place inside its own list, so this compares when they peaked and never how high.
Counted list by list. Two names in the same published list are measured on the same scale in the same year, so those comparisons are real — but positions from different lists are not, so nothing here is combined into an overall standing.
How this pair is related
The relationship kinds these two qualify for, each under its own stated rule. Every one is drawn from a list they both appear in.
- One moved ahead of the other
In 2005, Cillian moved ahead of Killian in Northern Ireland · Boys — #175 and #175 the year before became #178 and #205.
- Repeatedly exchanged positions
Cillian and Killian changed places 11 times in Republic of Ireland · Boys between 1970 and 2025, ending at #9 and #141.
- Closest over the longest run
Across 55 shared years in Republic of Ireland · Boys, Cillian and Killian averaged 47.0 places apart, ending at #9 and #141.
- Longest-running competitions
Cillian and Killian were both ranked in Republic of Ireland · Boys for 55 years, from 1970 to 2025, ending at #9 and #141.
- Peaked in the same years
Both reached their highest recorded position in England and Wales · Boys within 2 years — Cillian #177 in 2024, Killian #492 in 2022.
List by list
Republic of Ireland · Boys55 shared years, 1970–2025
Cillian held the stronger position in 28 of those years, Killian in 27.
Highest recorded here: Cillian #4 in 2024, Killian #55 in 2001.
The order changed in 2003: Cillian moved ahead. In 2002 they stood at #66 and #65; by 2003 that had become #60 and #67.
Most recent shared year, 2025: Cillian #9, Killian #141.
England and Wales · Boys29 shared years, 1996–2024
Cillian held the stronger position in 21 of those years, Killian in 8.
Highest recorded here: Cillian #177 in 2024, Killian #492 in 2022.
The order between them never changed and held in this list.
Most recent shared year, 2024: Cillian #177, Killian #638.
Northern Ireland · Boys27 shared years, 1997–2024
Cillian held the stronger position in 25 of those years, Killian in 0.
Highest recorded here: Cillian #2 in 2024, Killian #157 in 2017.
The order changed in 2005: Cillian moved ahead. In 2004 they stood at #175 and #175; by 2005 that had become #178 and #205.
Most recent shared year, 2024: Cillian #2, Killian #187.
Two names moving past each other in a ranking is a fact about the ranking. Namewise does not claim one name displaced the other, that families chose between them, or that either influenced the other — none of that is in this data.
Side by side
| Field | Cillian | Killian |
|---|---|---|
| Record type | Editorially researched profile | Official statistical record (evidence-only) |
| Gender usage | male | male |
| Meaning | Probably from Old Irish 'cell' (church) combined with a diminutive suffix. | Not yet recorded |
| Origin | Irish | Not yet recorded |
| Pronunciation | Not yet recorded | Not yet recorded |
| Syllables | 2 | 2 |
| Common variants / nicknames | Not yet recorded | Not yet recorded |
| Recorded regional usage | GB-ENW, GB-NIR, GB-SCT, IE | GB-ENW, GB-NIR, GB-SCT, IE |
| Most recent popularity observation | Republic of Ireland · Boys #9 (2025) | Republic of Ireland · Boys #141 (2025) |
| Pronunciation clarity (demonstration score) | Not yet recorded | Not yet recorded |
| Spelling simplicity (demonstration score) | 82/100 | 82/100 |
| International familiarity (demonstration score) | 100/100 | 100/100 |
| Data Confidence | medium | medium |
What the data shows
- Cillian has a recorded origin (Irish); Killian does not have one recorded yet.
- Cillian and Killian both have 2 syllables.
- A meaning is recorded for Cillian; Killian doesn't have one written yet.
- Both names have recorded usage in GB-ENW, GB-NIR, GB-SCT, IE.
How each name got here
Cillian
Popularity journey
First recorded1970
First recorded at #305 among boys in Republic of Ireland in 1970 — the earliest year that source publishes this name, not necessarily the earliest it was used.
Republic of Ireland · Boys
Highest recorded1997–2024
Highest recorded position: #2 among boys in Northern Ireland, in 2024 (recorded 1997–2024).
Northern Ireland · Boys
Most recent2025
Most recently recorded at #9 among boys in Republic of Ireland, in 2025.
Republic of Ireland · Boys
Killian
Popularity journey
First recorded1964
First recorded at #204 among boys in Republic of Ireland in 1964 — the earliest year that source publishes this name, not necessarily the earliest it was used.
Republic of Ireland · Boys
Highest recorded1964–2025
Highest recorded position: #55 among boys in Republic of Ireland, in 2001 (recorded 1964–2025).
Republic of Ireland · Boys
Most recent2025
Most recently recorded at #141 among boys in Republic of Ireland, in 2025.
Republic of Ireland · Boys