| Sullivan | Ronan | |
|---|---|---|
| Meaning | dark-eyed (disputed) | Little seal |
| Origin | irish | Irish |
| Gender | Boy | Boy |
| Pronunciation | SUHL-ih-vuhn | ROH-nun |
| Syllables | 3 | 2 |
| First appeared | 1884 | 1959 |
| Peak year | 2025 (1,083) | 2025 (1,406) |
| In 2025 | 1,083 | 1,406 |
| Trend | Near its peak | Near its peak |
Source: US Social Security Administration.
| Decade | Sullivan | Ronan |
|---|---|---|
| 2020s | 5,564 | 7,749 |
| 2010s | 6,428 | 9,092 |
| 2000s | 2,135 | 3,343 |
| 1990s | 535 | 322 |
| 1980s | 83 | 84 |
| 1970s | 86 | 32 |
| 1960s | 85 | 47 |
| 1950s | 129 | 10 |
| 1940s | 114 | 0 |
| 1930s | 110 | 0 |
| 1920s | 141 | 0 |
| 1910s | 122 | 0 |
| 1900s | 10 | 0 |
| 1890s | 63 | 0 |
| 1880s | 30 | 0 |
Anglicized from Irish O Suilleabhain, from 'suil' meaning 'eye' plus a second element usually read as 'dubh' (dark/black), giving 'dark-eyed'. The second element is disputed; alternative readings give 'one-eyed' or 'hawk-eyed', so the 'dark' sense is probable rather than certain.
Rónán means “little seal,” from the Irish rón.
Ronan is more popular than Sullivan today: about 1,406 US babies were given the name Ronan in 2025, compared with 1,083 named Sullivan.
Sullivan means dark-eyed (disputed) (irish origin), while Ronan means Little seal (Irish origin).
In US records, Sullivan first appears in 1884 and Ronan in 1959, so Sullivan has the longer recorded history.