List of state leaders in 400 BC Europe: South Roman Republic (complete list) –

| Type_ | Name_ | Title | Political_group | From_ |
|---|---|---|---|---|
| Sovereign | P. Licinius Calvus Esquilinus | Consular tribune | — | 400 BC |
| Sovereign | P. Maelius Capitolinus | Consular tribune | — | 400 BC |
| Sovereign | P. Manlius Vulso | Consular tribune | — | 400 BC |
| Sovereign | Sp. Furius Medullinus | Consular tribune | — | 400 BC |
| Sovereign | L. Titinius Pansa Saccus | Consular tribune | — | 400 BC |
| Sovereign | L. Publilius Philo Vulscus | Consular tribune | — | 400 BC |