Châtillon (; Valdôtain: ; Issime ); is a town and comune (municipality) in the autonomous region of the Aosta Valley in northwestern Italy. It has inhabitants.
Châtillon borders the municipalities of Antey-Saint-André, Ayas, Champdepraz, La Magdeleine, Montjovet, Pontey, Saint-Denis, Saint-Vincent, and Torgnon.
Châtillon was renamed "Castiglion Dora" in Italian in 1939 during Fascist rule in Italy. It was reverted to its original name in 1946.
Albard, Les Arsines, Assert, Bacquéret, Barat, La Barme-des-Antesans, Barmafol, Barmusse, Bellecombe, Bertinaz, Biaveusse, Les Biolasses, Biovre, Boësse, Les Boëttes, Breil-de-Barrel (Petit-Breil), Gros-Breil, Brun, Bourg, Le Brenvey, Breton, Brusoncles, Brusoncles-des-Gard (Brusoncles-Dessus), Brusoncles-des-Janin (Brusoncles-Dessous), Chaméran, Champ, Champeillon, Champ-Long, Champ-Cellier, Chardin, Chavod, Le Cheney, Chésallet, Cillod, Les Cloîtres, Closel, Conoz, Crêt-Blanc, Crêt-de-Breil, Le Crêt, Crétadonaz, Crétaz, Crétaz-Chardon, Les Dévies, Domianaz, L'ÃÂtavey, ÃÂtrop, Fontanellaz, La Fournaise, Les Fours, Francou, Grand-Freyan, Petit-Freyan, Frassiney, Garin, Jacquemet, Gléréyaz, Govergnou, Les Grands-Prés, Grange-de-Barme, Les ÃÂles, Isseuries, Larianaz, La Marcaz, Merlin, Murates, Mont-Ros, Morasset, Moriolaz, Neyran, Nissod, Nouarsaz, La Nouvaz, Pavirolaz, Les Pérolles, Perrianaz, Perry, Pie, Pissin, Plan-Pissin, Plantin, Pointé, Praz-Carral, Praz-Garin, Praz-Négoz, Prélaz, Promiod, Rumélaz, Revard, Saint-Valentin, Saint-Clair, Salé, La Salère, Sarmasse, Salèche, Selotaz, Serviou, Sétoret, Saix-de-Val, Soleil, Solettaz, Sopien, La Sounère, Taxard, Les Toles, Tollein, Toniquet, Tornafol, Tour-de-Grange, La Tour, Travod, Ussel, Varé, Ventoux, La Verdettaz, Verlex.
Châtillon is the ancestral home of the Bich family, whose most famous member was Marcel Bich, founder of Société Bic.