| Postal Code | Place Name | Region | Department | Arrondissement | Canton |
|---|---|---|---|---|---|
| 42000 | Saint-Étienne | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Étienne |
| 42100 | Saint-Étienne | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Étienne |
| 42110 | Feurs | Auvergne-Rhône-Alpes | Loire | Montbrison | Feurs |
| 42111 | Saint-Didier-sur-Rochefort | Auvergne-Rhône-Alpes | Loire | Montbrison | Boën-sur-Lignon |
| 42114 | Chirassimont | Auvergne-Rhône-Alpes | Loire | Roanne | Le Coteau |
| 42120 | Commelle-Vernay | Auvergne-Rhône-Alpes | Loire | Roanne | Le Coteau |
| 42122 | Saint-Marcel-de-Félines | Auvergne-Rhône-Alpes | Loire | Roanne | Le Coteau |
| 42123 | Saint-Cyr-de-Favières | Auvergne-Rhône-Alpes | Loire | Roanne | Le Coteau |
| 42130 | Boën-sur-Lignon | Auvergne-Rhône-Alpes | Loire | Montbrison | Boën-sur-Lignon |
| 42140 | Chazelles-sur-Lyon | Auvergne-Rhône-Alpes | Loire | Montbrison | Feurs |
| 42150 | La Ricamarie | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Etienne-2 |
| 42152 | L'Horme | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Chamond |
| 42153 | Riorges | Auvergne-Rhône-Alpes | Loire | Roanne | Roanne-2 |
| 42155 | Pouilly-les-Nonains | Auvergne-Rhône-Alpes | Loire | Roanne | Renaison |
| 42160 | Andrézieux-Bouthéon | Auvergne-Rhône-Alpes | Loire | Montbrison | Andrézieux-Bouthéon |
| 42170 | Saint-Just-Saint-Rambert | Auvergne-Rhône-Alpes | Loire | Montbrison | Saint-Just-Saint-Rambert |
| 42190 | Charlieu | Auvergne-Rhône-Alpes | Loire | Roanne | Charlieu |
| 42210 | Montrond-les-Bains | Auvergne-Rhône-Alpes | Loire | Montbrison | Andrézieux-Bouthéon |
| 42230 | Roche-la-Molière | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Étienne |
| 42240 | Unieux | Auvergne-Rhône-Alpes | Loire | Montbrison | Saint-Just-Saint-Rambert |
| 42260 | Saint-Germain-Laval | Auvergne-Rhône-Alpes | Loire | Roanne | Boën-sur-Lignon |
| 42270 | Saint-Priest-en-Jarez | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Etienne-5 |
| 42290 | Sorbiers | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Sorbiers |
| 42300 | Roanne | Auvergne-Rhône-Alpes | Loire | Roanne | Roanne-1 |
| 42310 | La Pacaudière | Auvergne-Rhône-Alpes | Loire | Roanne | Renaison |
| 42320 | La Grand-Croix | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Sorbiers |
| 42330 | Saint-Galmier | Auvergne-Rhône-Alpes | Loire | Montbrison | Andrézieux-Bouthéon |
| 42350 | La Talaudière | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Sorbiers |
| 42360 | Panissières | Auvergne-Rhône-Alpes | Loire | Montbrison | Feurs |
| 42370 | Renaison | Auvergne-Rhône-Alpes | Loire | Roanne | Renaison |
| 42380 | Luriecq | Auvergne-Rhône-Alpes | Loire | Montbrison | Saint-Just-Saint-Rambert |
| 42390 | Villars | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Etienne-4 |
| 42400 | Saint-Chamond | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Chamond |
| 42410 | Chavanay | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Le Pilat |
| 42420 | Lorette | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Rive-de-Gier |
| 42430 | Saint-Just-en-Chevalet | Auvergne-Rhône-Alpes | Loire | Roanne | Renaison |
| 42450 | Sury-le-Comtal | Auvergne-Rhône-Alpes | Loire | Montbrison | Saint-Just-Saint-Rambert |
| 42460 | Coutouvre | Auvergne-Rhône-Alpes | Loire | Roanne | Charlieu |
| 42470 | Saint-Symphorien-de-Lay | Auvergne-Rhône-Alpes | Loire | Roanne | Le Coteau |
| 42480 | La Fouillouse | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Sorbiers |
| 42490 | Fraisses | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Firminy |
| 42500 | Le Chambon-Feugerolles | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Etienne-2 |
| 42510 | Balbigny | Auvergne-Rhône-Alpes | Loire | Roanne | Le Coteau |
| 42520 | Maclas | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Le Pilat |
| 42530 | Saint-Genest-Lerpt | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Etienne-3 |
| 42550 | Usson-en-Forez | Auvergne-Rhône-Alpes | Loire | Montbrison | Saint-Just-Saint-Rambert |
| 42560 | Saint-Jean-Soleymieux | Auvergne-Rhône-Alpes | Loire | Montbrison | Montbrison |
| 42570 | Saint-Héand | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Sorbiers |
| 42580 | L'Étrat | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Sorbiers |
| 42590 | Neulise | Auvergne-Rhône-Alpes | Loire | Roanne | Le Coteau |
| 42600 | Montbrison | Auvergne-Rhône-Alpes | Loire | Montbrison | Montbrison |
| 42610 | Saint-Romain-le-Puy | Auvergne-Rhône-Alpes | Loire | Montbrison | Montbrison |
| 42620 | Saint-Martin-d'Estréaux | Auvergne-Rhône-Alpes | Loire | Roanne | Renaison |
| 42630 | Régny | Auvergne-Rhône-Alpes | Loire | Roanne | Charlieu |
| 42650 | Saint-Jean-Bonnefonds | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Saint-Etienne-5 |
| 42660 | Saint-Genest-Malifaux | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Le Pilat |
| 42670 | Belmont-de-la-Loire | Auvergne-Rhône-Alpes | Loire | Roanne | Charlieu |
| 42680 | Saint-Marcellin-en-Forez | Auvergne-Rhône-Alpes | Loire | Montbrison | Saint-Just-Saint-Rambert |
| 42700 | Firminy | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Firminy |
| 42720 | Pouilly-sous-Charlieu | Auvergne-Rhône-Alpes | Loire | Roanne | Charlieu |
| 42740 | Saint-Paul-en-Jarez | Auvergne-Rhône-Alpes | Loire | Saint-Étienne | Le Pilat |
| 42750 | Saint-Denis-de-Cabanne | Auvergne-Rhône-Alpes | Loire | Roanne | Charlieu |
| 42780 | Violay | Auvergne-Rhône-Alpes | Loire | Roanne | Le Coteau |
| 42810 | Rozier-en-Donzy | Auvergne-Rhône-Alpes | Loire | Montbrison | Feurs |
| 42820 | Ambierle | Auvergne-Rhône-Alpes | Loire | Roanne | Renaison |
| 42830 | Saint-Priest-la-Prugne | Auvergne-Rhône-Alpes | Loire | Roanne | Renaison |
| 42840 | Montagny | Auvergne-Rhône-Alpes | Loire | Roanne | Charlieu |
| 42890 | Sail-sous-Couzan | Auvergne-Rhône-Alpes | Loire | Montbrison | Boën-sur-Lignon |
| 42920 | Chalmazel | Auvergne-Rhône-Alpes | Loire | Montbrison | Boën-sur-Lignon |
| 42940 | Saint-Bonnet-le-Courreau | Auvergne-Rhône-Alpes | Loire | Montbrison | Boën-sur-Lignon |
| 42990 | Saint-Georges-en-Couzan | Auvergne-Rhône-Alpes | Loire | Montbrison | Boën-sur-Lignon |