Declining since 1998, #2,822 for girls today.
Popularity of Reilly since 1953
Babies named Reilly per year in U.S. Social Security records.
Data table (by decade)
| Decade | Girls | Boys |
|---|---|---|
| 1950s | 0 | 13 |
| 1960s | 0 | 0 |
| 1970s | 6 | 18 |
| 1980s | 108 | 206 |
| 1990s | 1,596 | 1,032 |
| 2000s | 2,437 | 1,916 |
| 2010s | 996 | 1,059 |
| 2020s | 385 | 316 |
Meaning & origin
Reilly, a surname-turned-given-name, entered the U.S. naming landscape in 1978 and saw its peak in 1998, when it ranked highest in usage. Since then, the name has followed a falling trajectory, reflecting a broader shift away from surname-style names that soared in the 1990s. By 2025, Reilly ranked 2,822, with about 1 in 26,788 newborns receiving the name. Its top states include New Jersey, Illinois, and Pennsylvania, suggesting a concentration in the Northeast and Midwest. The name's Irish roots and soft sound have kept it in steady, if diminished, use, appealing to families seeking a unisex option with a Celtic heritage.
Reilly is an anglicized form of the Irish surname Ó Raghallaigh, meaning 'descendant of Raghailleach.' The root Raghailleach may derive from elements meaning 'valiant' or 'race,' but its precise etymology is debated. Historically the name was borne by a powerful Gaelic family in County Cavan, and it transitioned to a given name in the 20th century, particularly in the United States.
Where Reilly is most popular
Births per 100,000 girls by state. Press play or drag the slider to watch it move across the decades. The lightest shade means too few recorded births.
Nicknames & variants
Nicknames: Rey, Riles
Sibling names for Reilly
Names that share Reilly's style, for a brother or sister.
