The Roseau Valley in St. Lucia is home to the island's largest banana plantation. The Roseau River runs through the valley and enters the sea at Roseau Bay. It is the longest river in St Lucia and the Roseau Reservoir is a major source of drinking water.

There are several settlements within the valley, These are Roseau, Jacmel, Bois d'Inde, Morne d'Or, Morne Ciseaux, Coolietown, Derriere Lagoon, Vanard and Millet.

Originally the valley had been used for the cultivation of sugar

Sugar

Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

 and a railway (since been lifted) was used to transport the sugar from further up the valley to a processing plant at Roseau. Until the 1980s there was a thriving farmer's and fisherman's market at Roseau, but since then most people now travel to the market at Castries

Castries

Castries , population 10,634, aggl. 37,963 , is the capital city of Saint Lucia, a country in the Caribbean. The district with the same name had a population of 61,341 in 2001-05-22, and stretches over an area of ....

. More recently, it is a major production area for bananas.

There is still a distillery at Roseau and it has produced several prize-winning rums.