Leo vs Theo
Leo and Theocompared 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.
England and Wales · Boys
In 2025, Leo was ranked #3 and Theo #12 among boys in England and Wales.
Scotland · Boys
In 2024, Leo was ranked #5 and Theo #4 among boys in Scotland.
New South Wales, Australia · Boys
In 2025, Leo was ranked #5 and Theo #32 among boys in New South Wales, Australia.
New Zealand · Boys
In 2023, Leo was ranked #5 and Theo #19 among boys in New Zealand.
Northern Ireland · Boys
In 2024, Leo was ranked #12 and Theo #5 among boys in Northern Ireland.
Republic of Ireland · Boys
In 2025, Leo was ranked #10 and Theo #21 among boys in Republic of Ireland.
Norway · Boys
In 2025, Leo was ranked #28 and Theo #22 among boys in Norway.
Leo and Theo over time
Leo and Theo appear together in 5 published lists, across 129 years of shared records. Leo held the stronger position in more years in 4 of them, Theo 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.
Theo reached its own highest recorded position earlier in 4 of those lists, Leo in 1. 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 2024, Theo moved ahead of Leo in Northern Ireland · Boys — #6 and #9 the year before became #12 and #5.
- Repeatedly exchanged positions
Leo and Theo changed places 4 times in Republic of Ireland · Boys between 1988 and 2025, ending at #10 and #21.
- Closest over the longest run
Across 30 shared years in England and Wales · Boys, Leo and Theo averaged 26.4 places apart, ending at #3 and #12.
- Longest-running competitions
Leo and Theo were both ranked in England and Wales · Boys for 30 years, from 1996 to 2025, ending at #3 and #12.
- Peaked in the same years
Both reached their highest recorded position in Northern Ireland · Boys within 2 years — Leo #6 in 2023, Theo #4 in 2022.
List by list
Norway · Boys36 shared years, 1986–2025
Leo held the stronger position in 17 of those years, Theo in 19.
Highest recorded here: Leo #28 in 2025, Theo #17 in 2024.
The order changed in 2007: Theo moved ahead. In 2006 they stood at #77 and #85; by 2007 that had become #81 and #79.
Most recent shared year, 2025: Leo #28, Theo #22.
England and Wales · Boys30 shared years, 1996–2025
Leo held the stronger position in 30 of those years, Theo in 0.
Highest recorded here: Leo #3 in 2025, Theo #9 in 2022.
The order between them never changed and held in this list.
Most recent shared year, 2025: Leo #3, Theo #12.
Republic of Ireland · Boys30 shared years, 1988–2025
Leo held the stronger position in 27 of those years, Theo in 3.
Highest recorded here: Leo #10 in 2025, Theo #13 in 2024.
The order between them never changed and held in this list.
Most recent shared year, 2025: Leo #10, Theo #21.
Northern Ireland · Boys23 shared years, 2001–2024
Leo held the stronger position in 19 of those years, Theo in 4.
Highest recorded here: Leo #6 in 2023, Theo #4 in 2022.
The order changed in 2024: Theo moved ahead. In 2023 they stood at #6 and #9; by 2024 that had become #12 and #5.
Most recent shared year, 2024: Leo #12, Theo #5.
New Zealand · Boys10 shared years, 2014–2023
Leo held the stronger position in 10 of those years, Theo in 0.
Highest recorded here: Leo #3 in 2019, Theo #19 in 2023.
The order between them never changed and held in this list.
Most recent shared year, 2023: Leo #5, Theo #19.
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 | Leo | Theo |
|---|---|---|
| Record type | Editorially researched profile | Editorially researched profile |
| Gender usage | male | male |
| Meaning | Lion. | Gift of God. |
| Origin | Latin | Greek, via Theodore/Theodora |
| Pronunciation | /ˈliːoʊ/ | /ˈθioʊ/ |
| Syllables | 1 | 1 |
| Common variants / nicknames | Not yet recorded | Teddy |
| Recorded regional usage | AU-NSW, GB-ENW, GB-NIR, GB-SCT, IE, NO, NZ | AU-NSW, GB-ENW, GB-NIR, GB-SCT, IE, NO, NZ |
| Most recent popularity observation | England and Wales · Boys #3 (2025) | England and Wales · Boys #12 (2025) |
| Pronunciation clarity (demonstration score) | 90/100 | 90/100 |
| Spelling simplicity (demonstration score) | 95/100 | 95/100 |
| International familiarity (demonstration score) | 100/100 | 100/100 |
| Data Confidence | medium | high |
What the data shows
- Leo is recorded with a Latin origin, while Theo is recorded with a Greek, via Theodore/Theodora origin.
- Leo and Theo both have 1 syllable.
- Leo's recorded meaning differs from Theo's — see the table above for each.
- Both names have recorded usage in AU-NSW, GB-ENW, GB-NIR, GB-SCT, IE, NO, NZ.
- The available evidence gives Leo a "medium" Data Confidence level and Theo a "high" level — this reflects how complete and corroborated the underlying evidence is, not a judgement of either name.
How each name got here
Leo
Popularity journey
First recorded1947
First recorded at #303 among boys in Norway in 1947 — the earliest year that source publishes this name, not necessarily the earliest it was used.
Norway · Boys
Highest recorded1996–2025
Highest recorded position: #3 among boys in England and Wales, in 2025 (recorded 1996–2025).
England and Wales · Boys
Most recent2025
Most recently recorded at #4867 among girls in England and Wales, in 2025.
England and Wales · Girls
Theo
Popularity journey
First recorded1986
First recorded at #637 among boys in Norway in 1986 — the earliest year that source publishes this name, not necessarily the earliest it was used.
Norway · Boys
Highest recorded2001–2024
Highest recorded position: #4 among boys in Northern Ireland, in 2022 (recorded 2001–2024).
Northern Ireland · Boys
Most recent2025
Most recently recorded at #12 among boys in England and Wales, in 2025.
England and Wales · Boys