Reilly: Baby Name Meaning, Nicknames and Numerology

What does the baby name “Reilly” mean?

Reilly is an Irish baby name tracing back to the ancient clan name O Raghallaigh, associated with a strong and storied lineage from the heart of Celtic Ireland, full of warmth and genuine heritage.

Origin of the baby name Reilly

Reilly derives from the Irish surname O Raghallaigh, meaning descendants of Raghallach. Raghallach is an old Gaelic personal name whose exact meaning is not fully agreed upon, but it is associated with a powerful early medieval Irish king of Connacht. The O Raghallaigh clan was prominent in County Cavan and across the province of Connacht, and the surname traveled widely as Irish communities spread around the world. The given-name use of Reilly follows the well-established and beloved tradition of adopting Irish clan surnames as first names.

Baby Reilly: The Idealist →

History of the baby name “Reilly”

The O Raghallaigh name is one of the oldest and most distinguished in Irish history, with roots going back to early medieval Connacht. As with many Irish surnames, Reilly moved into wider use as both a surname and a given name through the diaspora, particularly in the United States and Australia. The English-language expression the life of Reilly, meaning an easy and pleasant life, became widely known and gave the name an additionally cheerful and lighthearted association.

Why parents choose the baby name “Reilly”

Reilly is a name full of Irish warmth and charm, with a gentle rhythm that flows naturally for boys and girls alike. Its connection to the ancient O'Reilly clan gives it authentic Celtic heritage, and the cheerful idiom the life of Reilly adds a lighthearted quality that many parents genuinely love. It sits naturally and happily alongside names like Riley, Keeley, and Finley as one of the great Irish surname names.

Nicknames for the Baby Name “Reilly”

Re, Rey, Rein, Rekin, Rester, Reerino, Reinator

Nicknames from Around the World for the Baby Name “Reilly”

Terms of endearment for a baby name work differently around the world. Some cultures clip the name short, while others add an affectionate ending that can make it longer instead. Here is how the baby name Reilly might sound as a nickname in a few other languages and dialects.

Australian:

Reo, Rezza

British:

Res

German:

Reillychen

Irish:

Reen

Italian:

Reilletto

Spanish:

Reillito

Variations on the baby name “Reilly”

Reilly and Riley are the two most common spellings of this name and are often used interchangeably, with Riley being more widely used in many English-speaking countries. The surname form is typically O'Reilly or O'Riley in Irish tradition. The name sits in a broader family of Irish clan names that have crossed into given names, alongside names like Connor, Bryan, and Neil. Riley is the most widely recognized alternate spelling and remains very popular across English-speaking countries.