| Napoléon III - Emperor of the French | Sponsor of Haussmannian works and the Opera. |
| Baron Haussmann - Prefect of the Seine | Responsible for urban transformation in Paris. |
| Charles Garnier - Architect | Designer of the Palais Garnier bordering the square. |
| Hector Guimard - Architect Art Nouveau | Propose the metro entrances, finally rejected. |