Reilly: Meaning, Pronunciation and Origin
Reilly comes from the Irish surname Ó Raghallaigh, “descendant of Raghallach.” Here’s how to say it, where it comes from, and names that go well with it.
Updated September 2026
- Gender
- Boy
- Also spelled
- Riley
How do you pronounce Reilly?
Reilly is pronounced RYE-lee. It has two syllables, with the stress on the first. Other spellings: Riley.
What does Reilly mean?
Reilly is an Irish surname used as a first name. It is an English form of Ó Raghallaigh, “descendant of Raghallach.” The meaning of Raghallach itself is unknown, so the popular gloss “courageous, valiant” has no sound basis.
The O’Reillys were a powerful family of the same stock as the O’Rourkes. They were chiefs of Breifne O’Reilly, or East Breifne, which took in most of what is now Co. Cavan, and kept their independence as a clan until the reign of James I; five O’Reillys served as archbishops of Armagh. Riley, a common alternative spelling, can come from this Irish surname or from an English place name meaning “rye clearing.”
Sources: Behind the Name, Woulfe, Irish Names and Surnames (1923), Wikipedia.
How popular is Reilly in Ireland?
Reilly wasn't in the 2025 tables, which list names given to at least three babies. It was last recorded in 2023, when 3 baby boys got the name. It was most popular in 2018, when 4 baby boys were named Reilly, No. 635 that year. It first appears in the records in 2018, with 4 baby boys.
See the numbers by year
| Year | Babies | Rank |
|---|---|---|
| 2023 | 3 | No. 770 |
| 2021 | 3 | No. 755 |
| 2018 | 4 | No. 635 |
Reilly in Ogham
Ogham is the oldest way of writing Irish. It was carved along the edges of standing stones, mostly between the 4th and 6th centuries, and read from the bottom up. In later tradition each letter was named after a tree or plant. Here’s Reilly, letter by letter.
- RRuis, elder
- EEadhadh, aspen
- IIodhadh, yew
- LLuis, rowan
- LLuis, rowan
- IIodhadh, yew
Write any name in Ogham with our Ogham translator
Names that go with Reilly
Questions about Reilly
- How do you pronounce Reilly?
- Reilly is pronounced RYE-lee. Two syllables, stress on the first.
- Is Reilly a girl's name or a boy's name?
- Reilly is a boy's name.