boy's name
Iarlaith
EER-lah
- Origin Irish
- Gender Boy
- Letters 8
- Popularity Top 1000 (E&W)
- Births on record 690
Ireland
#85
2025 births
Iarlaith is a boy's name of Irish origin whose meaning is unresolved, borne by the founder of the monastic school at Tuam. It ranks 85th in Ireland and is at its peak in our records now.
- Iarlaith is a name of Irish origin.
- Peaked in Ireland in 2025, when 68 babies were given the name.
- It has been rising over the past decade in Ireland.
- Today about 1 in 36,861 babies in England and Wales is given this name.
- First appears in birth records in 1991.
Iarlaith over time
Births per decade in Ireland, 1990s to 2020s. Iarlaith is more popular in Northern Ireland — see the country table below. The striped bar is the 2020s, still in progress — it covers 2020 to 2025, not a full ten years.
Show the numbers
| Decade | Births |
|---|---|
| 1990s | 3 |
| 2000s | 33 |
| 2010s | 265 |
| 2020s (to 2025) | 321 |
What Iarlaith means
Iarlaith has no settled meaning. The second element is generally taken as flaith, a lord or prince, but the first has never been identified with confidence, so any full reading is a reconstruction rather than a translation.
Where Iarlaith comes from
Iarlaith is the Irish Iarlaithe, and its derivation is genuinely open. The ending is usually identified as flaith, a lord, prince or sovereignty — the same element in Faolán-type compounds — but the first syllable resists explanation. Reference sites frequently give tributary lord, taking the first element from iar, west or after, and that reading is a guess presented as a fact. A separate false trail runs through the English earl: Irish borrowed iarla, an earl, from the Norse jarl, but that borrowing happened centuries after the name is first recorded. Its bearer is Saint Iarlaithe of Tuam, a sixth-century founder whose monastic school taught Brendan the Navigator by tradition; he is the patron saint of the archdiocese of Tuam, and the anglicization Jarlath is standard in that part of Connacht.
Iarlaith in use
Iarlaith ranks 85th in Ireland with 68 births in 2025 and 136th in Northern Ireland, and it is rising in our data with a peak in 2025. Our records carry it from 1991. It does not appear in the British or American tables at all, which makes it one of a small number of names in this group that exist only on the island.
How popular is Iarlaith?
In 2024, Iarlaith was given to 16 babies in England and Wales, ranking #136 that year. It is well established in England and Wales.
Where Iarlaith is used
Irish figures withhold any name given to fewer than three babies in a year, so a gap means the name fell below that floor rather than went unused. The Central Statistics Office began recording the síneadh fada in 2018, so accented and unaccented spellings are counted separately from that year on. Data & sources.
How Iarlaith is spelled
Birth registers count each spelling separately, so every one has its own ranking.
| Spelling | What it is | Births on record |
|---|---|---|
| Íarlaith | Íarlaith is a rare spelling of Iarlaith, written with a fada and recorded 3 times, mostly in Ireland. | 3 |
Names that peaked alongside Iarlaith
These names rose and fell in the same era, which is why they tend to sound like they belong together.
Parents who like Iarlaith also like
Names whose popularity has risen and fallen in step with Iarlaith over the last century — the same taste, a different name.
Iarlaith in other languages
The same name as it is spelled elsewhere — not shortenings, and not different names that merely sound alike. Each one has its own record here.
- Irish
- Jarlath
Sibling names for Iarlaith
Names from the same era that won't rhyme or share an initial with Iarlaith — the two things that make a sibling set grate.
Common questions about Iarlaith
What does the name Iarlaith mean?
It is unresolved. The second element is generally taken as flaith, a lord, but the first has never been securely identified.
Does Iarlaith mean tributary lord?
That reading is widely repeated but is a reconstruction, not an established derivation.
Is Iarlaith related to the word earl?
No. Irish borrowed iarla from the Norse jarl centuries after this name is first recorded.
How do you pronounce Iarlaith?
EER-lah. The th is a soft h, not the English th.
How popular is the name Iarlaith?
In 2024, Iarlaith was given to 16 babies in England and Wales, ranking #136 that year. It is well established in England and Wales.
Is Iarlaith a girl's or a boy's name?
Iarlaith is given almost entirely to boys in birth records.
When was Iarlaith most popular?
Iarlaith peaked in 2025, when 68 babies were given the name. It has been rising over the past decade.
Is Iarlaith a good name?
That is not something records can settle, but they can tell you what you would be choosing. Iarlaith currently ranks #85 in Ireland. It has been rising over the past decade. Everything else — how it sounds with your surname, who it reminds you of — is yours.