In Ain · INSEE, recensement de la population
Saint-Genis-Pouilly is the youngest city in Ain, at 34.8 years, ahead of Gex (36.6 years) and Ferney-Voltaire (37.7 years). At the other end, Pérouges is the oldest city, at 44.1 years.
| Rank | City | Mean age | Population |
|---|---|---|---|
| 1 | Saint-Genis-Pouilly | 34.8 years | 14,432 |
| 2 | Gex | 36.6 years | 13,627 |
| 3 | Ferney-Voltaire | 37.7 years | 12,094 |
| 4 | Miribel | 39.3 years | 10,395 |
| 5 | Ambérieu-en-Bugey | 39.4 years | 15,934 |
| 6 | Valserhône | 40.4 years | 16,712 |
| 7 | Divonne-les-Bains | 40.5 years | 10,464 |
| 8 | Oyonnax | 40.8 years | 22,480 |
| 9 | Bourg-en-Bresse | 42.5 years | 42,372 |
| 10 | Pérouges | 44.1 years | 1,387 |
The same ranking for the whole of France : The youngest cities in France · The French cities with the oldest population
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.