| Aidan | Liam | |
|---|---|---|
| Meaning | Little fire | Resolute protector |
| Origin | irish | Irish |
| Gender | Boy | Boy |
| Pronunciation | AY-dən | LEE-am |
| Syllables | 2 | 2 |
| First appeared | 1936 | 1947 |
| Peak year | 2003 (10,067) | 2024 (22,252) |
| In 2025 | 1,043 | 20,818 |
| Trend | Declining | Near its peak |
Source: US Social Security Administration.
| Decade | Aidan | Liam |
|---|---|---|
| 2020s | 6,955 | 124,842 |
| 2010s | 25,446 | 174,017 |
| 2000s | 76,513 | 44,940 |
| 1990s | 8,783 | 11,904 |
| 1980s | 465 | 1,527 |
| 1970s | 172 | 784 |
| 1960s | 71 | 400 |
| 1950s | 21 | 117 |
| 1940s | 0 | 5 |
| 1930s | 5 | 0 |
Anglicized form of Aodhan, a diminutive of the Old Irish name Aodh, which means 'fire' and was borne by a Celtic sun/fire god. The name therefore reads as 'little fire' or 'fiery one'.
Liam is an Irish short form of William, itself from the Germanic Wilhelm — wil (will, desire) plus helm (helmet, protection) — giving the sense “resolute protector” or “strong-willed guardian.”
Liam is more popular than Aidan today: about 20,818 US babies were given the name Liam in 2025, compared with 1,043 named Aidan.
Aidan means Little fire (irish origin), while Liam means Resolute protector (Irish origin).
In US records, Aidan first appears in 1936 and Liam in 1947, so Aidan has the longer recorded history.