What does Leif mean?
Leif means “heir” or “descendant” in Old Norse.
What does Thor mean?
Thor is the Norse god of thunder, his name meaning “thunder” itself.
Leif vs Thor
Which is more popular?
Leif is more popular than Thor today: about 257 US babies were given the name Leif in 2025, compared with 44 named Thor.
| Leif | Thor | |
|---|---|---|
| Meaning | Heir, descendant | Thunder |
| Origin | Norse | Norse |
| Gender | Boy | Boy |
| Pronunciation | LAYF | THOR |
| Syllables | 1 | 1 |
| First appeared | 1912 | 1904 |
| Peak year | 2022 (290) | 2015 (118) |
| In 2025 | 257 | 44 |
| Trend | Near its peak | Steady |
Popularity over time, 1880–2025
Leif
Thor
Source: US Social Security Administration.
Births by decade
| Decade | Leif | Thor |
|---|---|---|
| 2020s | 1,542 | 415 |
| 2010s | 1,971 | 1,026 |
| 2000s | 1,329 | 699 |
| 1990s | 878 | 498 |
| 1980s | 1,231 | 469 |
| 1970s | 1,158 | 538 |
| 1960s | 886 | 568 |
| 1950s | 442 | 208 |
| 1940s | 196 | 137 |
| 1930s | 111 | 91 |
| 1920s | 126 | 117 |
| 1910s | 127 | 86 |
| 1900s | 0 | 5 |
Frequently asked questions
Is Leif or Thor more popular?
Leif is more popular than Thor today: about 257 US babies were given the name Leif in 2025, compared with 44 named Thor.
What is the difference between Leif and Thor?
Leif means Heir, descendant (Norse origin), while Thor means Thunder (Norse origin).
Which name is older, Leif or Thor?
In US records, Leif first appears in 1912 and Thor in 1904, so Thor has the longer recorded history.