Holding steady, #3,379 for boys today.
Popularity of Koji since 1922
Babies named Koji per year in U.S. Social Security records.
Data table (by decade)
| Decade | Boys |
|---|---|
| 1920s | 16 |
| 1930s | 0 |
| 1940s | 0 |
| 1950s | 0 |
| 1960s | 0 |
| 1970s | 27 |
| 1980s | 65 |
| 1990s | 73 |
| 2000s | 146 |
| 2010s | 169 |
| 2020s | 149 |
Meaning & origin
Koji is a Japanese masculine name that first appeared in U.S. birth records in 1922. As of 2025, it ranks 3,379th nationally, with an estimated 1 in 50,238 baby boys receiving the name that year. Its peak year so far is 2025, indicating a very gradual upward trend. The name is most common among families in California. Koji's meaning varies with the kanji chosen, making it a name that carries personal significance for each family.
Koji is a Japanese masculine name that can be written with various kanji combinations, giving it multiple possible meanings. Common kanji include 幸 (ko, meaning 'happiness') 司 (ji, meaning 'to administer') or 光 (ko, 'light') 司 (ji). It has been in consistent use in Japan for much of the 20th and 21st centuries.
Where Koji is most popular
Births per 100,000 boys by state, 2025. The lightest shade means too few recorded births.
Sibling names for Koji
Names that share Koji's style, for a brother or sister.
