In Ain · INSEE / geo.api.gouv.fr
Valserhône is the largest city by area in Ain, at 62.9 km², ahead of Oyonnax (36.1 km²) and Divonne-les-Bains (33.9 km²). At the other end, Ferney-Voltaire is the smallest city by area, at 4.8 km².
| Rank | City | City area | Population |
|---|---|---|---|
| 1 | Valserhône | 62.9 km² | 16,712 |
| 2 | Oyonnax | 36.1 km² | 22,480 |
| 3 | Divonne-les-Bains | 33.9 km² | 10,464 |
| 4 | Gex | 31.9 km² | 13,627 |
| 5 | Ambérieu-en-Bugey | 24.5 km² | 15,934 |
| 6 | Miribel | 24.5 km² | 10,395 |
| 7 | Bourg-en-Bresse | 24 km² | 42,372 |
| 8 | Pérouges | 19.3 km² | 1,387 |
| 9 | Saint-Genis-Pouilly | 9.8 km² | 14,432 |
| 10 | Ferney-Voltaire | 4.8 km² | 12,094 |
The same ranking for the whole of France : The largest communes in France by area · The smallest French cities by area
Scope: France, metropolitan and overseas, Corsica and the DROM included. This dataset holds every commune of 10,000 inhabitants or more, plus smaller communes famous enough to be household names, 1,131 in all. It is not the full list of 35,000 French communes, so a village can sit outside a ranking whose extreme it would otherwise hold.
Method and sources: populations are the INSEE legal populations, boundaries and coordinates come from the IGN commune registry, both served by geo.api.gouv.fr. Density is the population divided by the commune's area; distances are measured as the crow flies from the commune's centre. Data read on August 28, 2026.