The Pays de Caux (pronounced: [pɛi də ko]) is an area in Normandy occupying the greater part of the French département of Seine Maritime in Haute-Normandie. It is a chalk plateau to the north of the Seine Estuary and extending to the cliffs on the English Channel coast; its coastline is known as the Côte d'Albâtre. In the east, it borders on the Pays de Bray where the strata below the chalk show through.
Cauchois is a notable dialect of the Norman language. The Pays de Caux is one of the remaining strongholds of the Norman language outside the Cotentin.
The principal settlements are Le Havre, Dieppe, Fécamp, Yvetot and Étretat.
In the Norman language caux means lime, calcium carbonate. In French, for comparison, the word is chaux (the French 'ch' being pronounced as an English 'sh'. Example: Caux dialect candelle, English candle, French chandelle ). The name of the neighbouring Pays de Bray comes from an Old French word of Gaulish origin for mud. They appear to be so named as their soils distinguish them; the one of sticky clay, the other on dry chalk, but that is only a legend. In fact, according to something common in the former Gaul, the name derives from the Celtic tribe that lived here in ancient time: the Caletes (or Caleti. It means "the hard or the courageous people", Breton kaled hard, Welsh caled hard ) and this land was their territory. They are sometimes considered as Belgae or as Armoricans. The word Caletes shifted to *Caltes, then *Calz, Cauz, to be spelled "Caux" in modern time.