| Castelmoron-d'Albret | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Castelmoron-d'Albret (Gironde).svg |
| Arrondissement: | Langon |
| Canton: | Le Réolais et Les Bastides |
| Insee: | 33103 |
| Postal Code: | 33540 |
| Mayor: | André Greze[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 44.6806°N -0.0106°W |
| Elevation M: | 80 |
| Elevation Min M: | 37 |
| Elevation Max M: | 61 |
| Area Km2: | 0.0354 |
Castelmoron-d'Albret (in French pronounced as /kastɛlmɔʁɔ̃ dalbʁɛ/; Occitan (post 1500);: Castèlmauron d'Albret) is a commune in the Gironde department in Nouvelle-Aquitaine in south-western France.
It is notable for being the smallest commune in France by size, with an area of just 3.54ha, roughly the size of the Place Charles de Gaulle in Paris. By comparison, the largest commune in metropolitan France is Arles, with an area of 759km2. It is the smallest commune in France, and is smaller than the nations of Monaco and Vatican City.