Cillian vs Oliver
Cillian and Olivercompared 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 Oliver #10 among boys in Northern Ireland.
England and Wales · Boys
In 2024, Cillian was ranked #177 and Oliver #3 among boys in England and Wales.
Scotland · Boys
In 2024, Cillian was ranked #83 and Oliver #7 among boys in Scotland.
Republic of Ireland · Boys
In 2025, Cillian was ranked #9 and Oliver #18 among boys in Republic of Ireland.
Cillian and Oliver over time
Cillian and Oliver appear together in 3 published lists, across 112 years of shared records. Oliver held the stronger position in more years in 2 of them, Cillian in 1.
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.
Oliver 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 2023, Cillian moved ahead of Oliver in Northern Ireland · Boys — #9 and #6 the year before became #4 and #8.
- Closest over the longest run
Across 28 shared years in Northern Ireland · Boys, Cillian and Oliver averaged 55.4 places apart, ending at #2 and #10.
- Longest-running competitions
Cillian and Oliver were both ranked in Republic of Ireland · Boys for 55 years, from 1970 to 2025, ending at #9 and #18.
List by list
Republic of Ireland · Boys55 shared years, 1970–2025
Cillian held the stronger position in 38 of those years, Oliver in 17.
Highest recorded here: Cillian #4 in 2024, Oliver #14 in 1975.
The order changed in 1988: Cillian moved ahead. In 1987 they stood at #110 and #103; by 1988 that had become #120 and #137.
Most recent shared year, 2025: Cillian #9, Oliver #18.
England and Wales · Boys29 shared years, 1996–2024
Cillian held the stronger position in 0 of those years, Oliver in 29.
Highest recorded here: Cillian #177 in 2024, Oliver #1 in 2009.
The order between them never changed and held in this list.
Most recent shared year, 2024: Cillian #177, Oliver #3.
Northern Ireland · Boys28 shared years, 1997–2024
Cillian held the stronger position in 2 of those years, Oliver in 26.
Highest recorded here: Cillian #2 in 2024, Oliver #3 in 2016.
The order changed in 2023: Cillian moved ahead. In 2022 they stood at #9 and #6; by 2023 that had become #4 and #8.
Most recent shared year, 2024: Cillian #2, Oliver #10.
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 | Oliver |
|---|---|---|
| Record type | Editorially researched profile | Editorially researched profile |
| Gender usage | male | male |
| Meaning | Probably from Old Irish 'cell' (church) combined with a diminutive suffix. | Commonly interpreted as 'olive tree', though the true root is debated. |
| Origin | Irish | Old French |
| Pronunciation | Not yet recorded | /ˈɒlɪvər/ |
| Syllables | 2 | 3 |
| Common variants / nicknames | Not yet recorded | Ollie, Olivier, Oliviero |
| Recorded regional usage | GB-ENW, GB-NIR, GB-SCT, IE | AU-NSW, GB-ENW, GB-NIR, GB-SCT, IE, NO, NZ |
| Most recent popularity observation | Republic of Ireland · Boys #9 (2025) | United Kingdom #1 (2025) |
| Pronunciation clarity (demonstration score) | Not yet recorded | 90/100 |
| Spelling simplicity (demonstration score) | 82/100 | 88/100 |
| International familiarity (demonstration score) | 100/100 | 100/100 |
| Data Confidence | medium | medium |
What the data shows
- Cillian is recorded with a Irish origin, while Oliver is recorded with a Old French origin.
- Cillian has 2 syllables, compared with 3 for Oliver.
- Cillian's recorded meaning differs from Oliver's — see the table above for each.
- 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
Oliver
Popularity journey
First recorded1959
First recorded at #478 among boys in Norway in 1959 — the earliest year that source publishes this name, not necessarily the earliest it was used.
Norway · Boys
Highest recorded1996–2024
Highest recorded position: #1 among boys in England and Wales, in 2009 (recorded 1996–2024).
England and Wales · Boys
Most recent2025
Most recently recorded at #2 among boys in New South Wales, Australia, in 2025.
New South Wales, Australia · Boys