| Liam | Aidan | |
|---|---|---|
| Meaning | Resolute protector | Little fire |
| Origin | Irish | irish |
| Gender | Boy | Boy |
| Pronunciation | LEE-am | AY-dən |
| Syllables | 2 | 2 |
| First appeared | 1947 | 1936 |
| Peak year | 2024 (22,252) | 2003 (10,067) |
| In 2025 | 20,818 | 1,043 |
| Trend | Near its peak | Declining |
Source: US Social Security Administration.
| Decade | Liam | Aidan |
|---|---|---|
| 2020s | 124,842 | 6,955 |
| 2010s | 174,017 | 25,446 |
| 2000s | 44,940 | 76,513 |
| 1990s | 11,904 | 8,783 |
| 1980s | 1,527 | 465 |
| 1970s | 784 | 172 |
| 1960s | 400 | 71 |
| 1950s | 117 | 21 |
| 1940s | 5 | 0 |
| 1930s | 0 | 5 |
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.”
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 more popular than Aidan today: about 20,818 US babies were given the name Liam in 2025, compared with 1,043 named Aidan.
Liam means Resolute protector (Irish origin), while Aidan means Little fire (irish origin).
In US records, Liam first appears in 1947 and Aidan in 1936, so Aidan has the longer recorded history.